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Kawasaki KX250F - Service Manual - General Information

Manual is about: Motorcycle

Summary of KX250F -

  • Page 1

    Kx250f motorcycle service manual.

  • Page 3: Quick Reference Guide

    This quick reference guide will assist you in locating a desired topic or pro- cedure. •bend the pages back to match the black tab of the desired chapter num- ber with the black tab on the edge at each table of contents page. •refer to the sectional table of contents for the exact pages to locate th...

  • Page 5: Kx250F

    Kx250f motorcycle service manual all rights reserved. No parts of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic mechanical photocopying, recording or otherwise, without the prior written permission of quality assurance divisi...

  • Page 6

    List of abbreviations a ampere(s) lb pound(s) abdc after bottom dead center m meter(s) ac alternating current min minute(s) atdc after top dead center n newton(s) bbdc before bottom dead center pa pascal(s) bdc bottom dead center ps horsepower btdc before top dead center psi pound(s) per square inch...

  • Page 7: Foreword

    Foreword this manual is designed primarily for use by trained mechanics in a properly equipped shop. However, it contains enough detail and basic in- formation to make it useful to the owner who de- sires to perform his own basic maintenance and repair work. A basic knowledge of mechanics, the prope...

  • Page 9: General Information

    General information 1-1 1 general information table of contents before servicing ..................................................................................................................... 1-2 model identification................................................................................

  • Page 10

    1-2 general information before servicing before starting to perform an inspection service or carry out a disassembly and reassembly opera- tion on a motorcycle, read the precautions given below. To facilitate actual operations, notes, illustra- tions, photographs, cautions, and detailed descriptions...

  • Page 11

    General information 1-3 before servicing storage of removed parts after all the parts including subassembly parts have been cleaned, store the parts in a clean area. Put a clean cloth or plastic sheet over the parts to protect from any foreign materials that may collect before re-assembly. Inspectio...

  • Page 12

    1-4 general information before servicing tightening torque incorrect torque applied to a bolt, nut, or screw may lead to serious damage. Tighten fasteners to the specified torque using a good quality torque wrench. Often, the tightening sequence is followed twice-initial tightening and final tighten...

  • Page 13

    General information 1-5 before servicing ball bearing and needle bearing do not remove pressed ball or needle unless removal is absolutely necessary. Replace with new ones whenever removed. Press bearings with the manufacturer and size marks facing out. Press the bearing into place by putting pressu...

  • Page 14

    1-6 general information before servicing direction of engine rotation when rotating the crankshaft by hand, the free play amount of rotating direction will affect the adjustment. Ro- tate the crankshaft to positive direction (clockwise viewed from output side). Electrical leads a two-color lead is i...

  • Page 15

    General information 1-7 model identification kx250yb left side view kx250yb right side view frame number engine number.

  • Page 16

    1-8 general information general specifications items kx250yb ∼ yc dimensions overall length 2 170 mm (85.43 in.) overall width 820 mm (32.3 in.) overall height 1 270 mm (50.00 in.) wheelbase 1 475 mm (58.07 in.) road clearance 330 mm (13.0 in.) seat height 945 mm (37.2 in.) curb mass: kx250yb 105.7 ...

  • Page 17

    General information 1-9 general specifications items kx250yb ∼ yc engine oil: grade api sg, sh, sj, sl or sm with jaso ma, ma1 or ma2 viscosity sae 10w-40 capacity 1.0 l (1.1 us qt) drive train primary reduction system: type gear reduction ratio 3.350 (67/20) clutch type wet multi disc, manual trans...

  • Page 18

    1-10 general information general specifications items kx250yb ∼ yc effective disc diameter: front 225 mm (8.86 in.) rear 215 mm (8.46 in.) specifications are subject to change without notice, and may not apply to every country..

  • Page 19

    General information 1-11 technical information - dual injector overview although the kawasaki ninja super-sports models are already equipped with dual injectors, the 2012 kx250yc is the first motocross model to adopt dual-injector technology. The dual injectors are installed in the throttle body and...

  • Page 20

    1-12 general information technical information - dual injector image of the fuel injection field a. Throttle opening b. Engine speed c. Fuel injection field of both injector.

  • Page 21

    General information 1-13 unit conversion table prefixes for units: prefix symbol power mega m × 1 000 000 kilo k × 1 000 centi c × 0.01 milli m × 0.001 micro µ × 0.000001 units of mass: kg × 2.205 = lb g × 0.03527 = oz units of volume: l × 0.2642 = gal (us) l × 0.2200 = gal (imp) l × 1.057 = qt (us)...

  • Page 23: Periodic Maintenance

    Periodic maintenance 2-1 2 periodic maintenance table of contents periodic maintenance chart ................................................................................................... 2-3 torque and locking agent..................................................................................

  • Page 24

    2-2 periodic maintenance brakes.................................................................................................................................. 2-37 brake lever and pedal adjustment .................................................................................. 2-37 brake fluid ...

  • Page 25

    Periodic maintenance 2-3 periodic maintenance chart the maintenance must be done in accordance with this chart to keep the motorcycle in good running condition. Frequency operation each race or 2.5 hours every 3 races or 7.5 hours every 6 races or 15 hours every 12 races or 30 hours see page spark p...

  • Page 26

    2-4 periodic maintenance periodic maintenance chart frequency operation each race or 2.5 hours every 3 races or 7.5 hours every 6 races or 15 hours every 12 races or 30 hours see page wheels/tires - inspect • 2-32 rear sprocket - inspect † • 2-36 front fork - clean and inspect • 2-47 front fork oil ...

  • Page 27

    Periodic maintenance 2-5 torque and locking agent tighten all bolts and nuts to the proper torque using an accurate torque wrench. If insufficiently tightened, a bolt or nut may become damaged, strip an internal thread, or break and then fall out. The following table lists the tightening torque for ...

  • Page 28

    2-6 periodic maintenance torque and locking agent torque fastener n·m kgf·m ft·lb remarks cylinder head bolts (m10) 49 5.0 36 s, mo cylinder head bolts (m6) 12 1.2 106 in·lb s plug 20 2.0 15 l throttle body clamp screw 2.0 0.20 18 in·lb throttle body holder clamp screw 2.0 0.20 18 in·lb cylinder bol...

  • Page 29

    Periodic maintenance 2-7 torque and locking agent torque fastener n·m kgf·m ft·lb remarks kick pedal bolt 25 2.5 18 l kick ratchet guide bolt 8.8 0.90 78 in·lb l ratchet plate bolt 9.8 1.0 87 in·lb l, s ratchet plate screw 15 1.5 11 l, s shift drum cam bolt 24 2.4 18 l gear positioning lever nut 8.8...

  • Page 30

    2-8 periodic maintenance torque and locking agent torque fastener n·m kgf·m ft·lb remarks left front fork adjuster assembly 69 7.0 51 l pressure relief screws 1.3 0.13 12 in·lb right front fork top plug 34 3.5 25 right front fork piston rod nut 20 2.0 15 right front fork bottom plug 69 7.0 51 l swin...

  • Page 31

    Periodic maintenance 2-9 torque and locking agent basic torque for general fasteners threads diameter torque (mm) n·m kgf·m ft·lb 5 3.4 ∼ 4.9 0.35 ∼ 0.50 30 ∼ 43 in·lb 6 5.9 ∼ 7.8 0.60 ∼ 0.80 52 ∼ 69 in·lb 8 14 ∼ 19 1.4 ∼ 1.9 10.0 ∼ 13.5 10 25 ∼ 34 2.6 ∼ 3.5 19.0 ∼ 25 12 44 ∼ 61 4.5 ∼ 6.2 33 ∼ 45 14...

  • Page 32

    2-10 periodic maintenance specifications item standard service limit fuel system throttle grip free play 2 ∼ 3 mm (0.08 ∼ 0.12 in.) – – – idle speed 2 050 ±50 r/min (rpm) – – – air cleaner element oil high quality foam air filter oil – – – cooling system coolant: type (recommended) permanent type an...

  • Page 33

    Periodic maintenance 2-11 specifications item standard service limit wheels/tires rim runout (with tire installed): axial tir 1.0 mm (0.04 in.) or less tir 2.0 mm (0.08 in.) radial tir 1.0 mm (0.04 in.) or less tir 2.0 mm (0.08 in.) tires air pressure (front/rear) 100 kpa (1.00 kgf/cm², 14 psi) – – ...

  • Page 34

    2-12 periodic maintenance specifications item standard service limit capacity (right front fork) 155 ±2.5 ml (5.24 ±0.085 us oz.) (kx250yb) 205 ±2.5 ml (6.93 ±0.085 us oz.) (kx250yc) 130 ∼ 500 ml (4.4 ∼ 16.9 us oz.) (kx250yb) 130 ∼ 492 ml (4.4 ∼ 16.6 us oz.) (kx250yc) rear shock absorber oil: viscos...

  • Page 35

    Periodic maintenance 2-13 special tools inside circlip pliers: 57001-143 steering stem nut wrench: 57001-1100 jack: 57001-1238 attachment jack: 57001-1252 fork oil level gauge: 57001-1290 fork piston rod puller, m10 × 1.0: 57001-1298 filler cap driver: 57001-1454 fork spring compressor: 57001-1587 j...

  • Page 36

    2-14 periodic maintenance special tools clamp: 57001-1693 base and extension rod: 57001-1753.

  • Page 37

    Periodic maintenance 2-15 periodic maintenance procedures fuel system fuel hose and connections inspection ○ if the motorcycle is not properly handled, the high pres- sure inside the fuel line can cause fuel to leak [a] or the hose burst. Replace the fuel hose if any fraying, cracks [b] or bulges [c...

  • Page 38

    2-16 periodic maintenance periodic maintenance procedures throttle body cleaning • check the throttle bore for cleanliness as follows. ○ remove the throttle body assy (see throttle body assy removal in the fuel system (dfi) chapter). ○ check the throttle bore [a] at the throttle valve for carbon dep...

  • Page 39

    Periodic maintenance 2-17 periodic maintenance procedures idle speed inspection notice this motorcycle is designed for competition use only. Therefore, the radiator does not incorporate a coolant reserve tank or cooling fan. Prolonged idling of the engine with no airflow through the radiator can cau...

  • Page 40

    2-18 periodic maintenance periodic maintenance procedures air cleaner element cleaning and inspection note ○ in dusty areas, the element should be cleaned more frequently than recommended interval. ○ after riding through rain or on muddy roads, the element should be cleaned immediately. ○ since repe...

  • Page 41

    Periodic maintenance 2-19 periodic maintenance procedures • clean the element [a] in a bath of a high-flash point sol- vent using a soft bristle brush. • squeeze it dry in a clean towel [a]. Do not wring the ele- ment or blow it dry; the element can be damaged. • check all parts of the element for v...

  • Page 42

    2-20 periodic maintenance periodic maintenance procedures fuel tank clean warning gasoline and low-flash point solvents can be flammable and/or explosive and cause severe burns. Clean the tank in a well-ventilated area, and take care that there are no sparks or flame any- where near the working area...

  • Page 43

    Periodic maintenance 2-21 periodic maintenance procedures • check the coolant level. The coolant level [a] should be at the bottom of the filler neck [b]. If the coolant level is low, add coolant through the filler opening to the bottom of the filler neck. Install the cap. Recommended coolant perman...

  • Page 44

    2-22 periodic maintenance periodic maintenance procedures water hoses and connections inspection • remove the radiator shroud (see radiator removal in the cooling system chapter). ○ the high pressure inside the water hoses [a] can cause coolant to leak [b] or the hose to burst if the line is not pro...

  • Page 45

    Periodic maintenance 2-23 periodic maintenance procedures • using a thickness gauge [a], measure the clearance be- tween each cam lobe and valve lifter for all 4 valves. ○ for the purpose of adjusting the valve clearances, record the measured values. Valve clearance standard: exhaust 0.17 ∼ 0.22 mm ...

  • Page 46

    2-24 periodic maintenance periodic maintenance procedures adjustment shims thick- ness p/no. Mark thick- ness p/no. Mark 2.500 92180-0167 250 3.025 92180-0188 302 2.525 92180-0168 252 3.050 92180-0189 305 2.550 92180-0169 255 3.075 92180-0190 308 2.575 92180-0170 258 3.100 92180-0191 310 2.600 92180...

  • Page 47

    Periodic maintenance 2-25 periodic maintenance procedures cylinder head warp inspection • remove the cylinder head (see cylinder head removal in the engine top end chapter). • lay a straightedge [a] across the lower surface of the head at several different points, and measure warp by inserting a thi...

  • Page 48

    2-26 periodic maintenance periodic maintenance procedures piston/cylinder clearance inspection the piston-to-cylinder clearance is measured whenever a piston or cylinder is replaced with a new one. The standard piston-to-cylinder clearance must be adhered to whenever the cylinder is replaced. If onl...

  • Page 49

    Periodic maintenance 2-27 periodic maintenance procedures • insert the new silencer wool [a] and muffler cover [b]. ○ fit the muffler pipe end [c] and the exhaust hole of the baffle. • apply a non-permanent locking agent to the muffler cover bolts, and tighten them. • tighten: torque - muffler mount...

  • Page 50

    2-28 periodic maintenance periodic maintenance procedures • remove the number plate (see front fork removal in the suspension chapter). • loosen the locknut [a] at the clutch cable, and turn the adjusting nut [b] so that clutch lever has 8 ∼ 13 mm (0.3 ∼ 0.5 in.) of play. • tighten the locknut, and ...

  • Page 51

    Periodic maintenance 2-29 periodic maintenance procedures engine oil change • warm up the engine thoroughly so that the oil will pick up any sediment and drain easily. Then stop the engine. • place an oil pan beneath the engine. • remove the oil filler plug [a]. Special tool - filler cap driver: 570...

  • Page 52

    2-30 periodic maintenance periodic maintenance procedures oil filter change • drain: engine oil (see engine oil change) • remove: oil filter cap bolts [a] oil filter cap [b] • remove the oil filter [a]. • replace the oil filter with a new one. • apply grease to the grommet [a]. • install the oil fil...

  • Page 53

    Periodic maintenance 2-31 periodic maintenance procedures crankshaft/transmission crankshaft inspection • remove: cylinder head (see cylinder head removal in the en- gine top end chapter) cylinder (see cylinder removal in the engine top end chapter) piston (see piston removal in the engine top end c...

  • Page 54

    2-32 periodic maintenance periodic maintenance procedures tires inspection • remove any imbedded stones or other foreign particles from the tread. Repair or replace with a new one if necessary. • visually inspect the tire for cracks and cuts. Replace the tire, if any damage are noticed. ○ swelling o...

  • Page 55

    Periodic maintenance 2-33 periodic maintenance procedures • set a dial gauge against the side of the rim, and rotate the rim to measure the axial runout [a]. ○ the difference between the highest and lowest dial read- ings is the amount of runout. • set a dial gauge against the outer circumference of...

  • Page 56

    2-34 periodic maintenance periodic maintenance procedures • stretch the chain taut by hanging a 10 kg (22 lb) weight [a] on the chain. • measure the length of 20 links [b] on the straight part [c] of the chain from the pin center of the 1st pin to the pin center of the 21st pin. Since the chain may ...

  • Page 57

    Periodic maintenance 2-35 periodic maintenance procedures drive chain slack adjustment • loosen the left and right chain adjuster locknuts [a]. • remove the cotter pin [b] and loosen the axle nut [c]. If the chain is too tight, back out the left and right chain adjusting bolts [d] evenly, and push t...

  • Page 58

    2-36 periodic maintenance periodic maintenance procedures drive chain lubrication ○ the chain should be lubricated with a lubricant which will both prevent the exterior from rusting and also absorb shock and reduce friction in the interior of the chain. If the chain is especially dirty, it should be...

  • Page 59

    Periodic maintenance 2-37 periodic maintenance procedures brakes brake lever and pedal adjustment • slide the dust cover [a]. • adjust the brake lever to suit you. ○ loosen the adjuster locknut [b] and turn the adjuster [c] to either side. • after adjustment, tighten the locknut. Warning an improper...

  • Page 60

    2-38 periodic maintenance periodic maintenance procedures brake fluid level inspection • check the brake fluid level in the front or rear brake reser- voir [a] and the front or rear reservoir must be kept above the lower level line [b]. Note ○ hold the reservoir horizontal when checking brake fluid ...

  • Page 61

    Periodic maintenance 2-39 periodic maintenance procedures brake fluid change warning when working with the disc brake, observe the pre- cautions listed below. 1. Never reuse old brake fluid. 2. Do not use fluid from a container that has been left unsealed or that has been open for a long time. 3. Do...

  • Page 62

    2-40 periodic maintenance periodic maintenance procedures • remove the rubber cap [a] on the bleed valve [b]. • attach a clear plastic hose [a] to the bleed valve on the caliper, and run the other end of the hose into a container. • change the brake fluid as follows: ○ repeat this operation until fr...

  • Page 63

    Periodic maintenance 2-41 periodic maintenance procedures brake pad wear inspection • check the lining thickness and condition of the brake pads in each caliper. Note ○ it is able to check with the pads installed. If either pad is damaged, replace both pads in the caliper as a set. Brake pad lining ...

  • Page 64

    2-42 periodic maintenance periodic maintenance procedures • slide the dust cover [a] on the push rod [b] out of place, and remove the circlip [c]. Special tool - inside circlip pliers: 57001-143 • pull out the push rod. • take off the piston assy [d]. Assembly • before assembly, clean all parts incl...

  • Page 65

    Periodic maintenance 2-43 periodic maintenance procedures • separate the caliper holder [a] from the caliper [b]. • remove the anti-rattle spring [c]. • using compressed air, remove the pistons. One way to remove the pistons is as follows. ○ cover the caliper opening with a clean, heavy cloth [a]. ○...

  • Page 66

    2-44 periodic maintenance periodic maintenance procedures • using compressed air, remove the piston. ○ cover the caliper opening with a clean, heavy cloth [a]. ○ remove the piston by lightly applying compressed air [b] to the hose joint opening. Warning the piston in the brake caliper can crush hand...

  • Page 67

    Periodic maintenance 2-45 periodic maintenance procedures • install the anti-rattle springs [a] as shown in the figure. • replace the shaft rubber boot [a] and dust boot [b] if they are damaged. • apply a thin coat of pbc (poly butyl cuprysil) grease to the caliper holder shafts [c] and holder holes...

  • Page 68

    2-46 periodic maintenance periodic maintenance procedures brake hoses and connections inspection • inspect the brake hose and fittings for deterioration, cracks and signs of leakage. ○ the high pressure inside the brake line can cause fluid to leak [a] or the hose to burst if the line is not properl...

  • Page 69

    Periodic maintenance 2-47 periodic maintenance procedures • remove the front/rear brake hose banjo bolts [a] and washers [b]. • replace the washers with new ones. ○ when removing the brake hose, take care not to spill the brake fluid on the painted or plastic parts. ○ when removing the brake hose, t...

  • Page 70

    2-48 periodic maintenance periodic maintenance procedures • remove: bolts [a] and brake hose clamp [b] bolts [c] and guard [d] caliper mounting bolts [e] front wheel (see front wheel removal in the wheels/tires chapter) ○ rest the caliper [a] on a stand [b] so that it does not dan- gle. • loosen the...

  • Page 71

    Periodic maintenance 2-49 periodic maintenance procedures • unscrew the left front fork cylinder unit [a] from the outer tube [b]. Special tool - top plug wrench, 50 mm: 57001-1645 • slowly slide down the outer tube. • hold the left front fork tube [a] upside down over a clean container [b] and drai...

  • Page 72

    2-50 periodic maintenance periodic maintenance procedures • remove the push rod [a]. Notice removing the locknut and pushing the piston rod thread into the left front fork cylinder unit will dam- age the oil seal. Do not remove the locknut from the piston rod. • remove the fork leg from the vise. • ...

  • Page 73

    Periodic maintenance 2-51 periodic maintenance procedures • hold the left front fork cylinder unit [a] upside down over a clean container [b] and drain the oil. Note ○ pump the piston rod up and down to discharge the fork oil. • hold the front fork at the inverted position for more than 20 minutes t...

  • Page 74

    2-52 periodic maintenance periodic maintenance procedures • apply fork oil to the sliding surface of the piston rod. • purge the air from the fork cylinder [a] by gently moving [b] the piston rod up and down several times. • with the piston rod fully stretched, check the oil level in the left front ...

  • Page 75

    Periodic maintenance 2-53 periodic maintenance procedures • hold the top plug wrench [a] with a vise. • hold the left front fork cylinder unit [b] with the top plug wrench. • tighten the left front fork base valve assembly [c]. Special tool - top plug wrench, 50 mm: 57001-1645 torque - left front fo...

  • Page 76

    2-54 periodic maintenance periodic maintenance procedures • protect the piston rod end with a heavy cloth to prevent damage. • check the piston rod for smooth operation. ○ pump the piston rod [a] to full stroke [b] by pushing down the left front fork cylinder unit [c]. If the piston rod operation is...

  • Page 77

    Periodic maintenance 2-55 periodic maintenance procedures • wipe the fork oil off completely from the left front fork cylin- der unit [a]. • install the left front fork cylinder unit into the fork. • temporarily tighten the left front fork cylinder unit using the top plug wrench. Special tool - top ...

  • Page 78

    2-56 periodic maintenance periodic maintenance procedures • turn the locknut [a] counterclockwise until it contacts with the left front fork adjuster assembly [b]. • with the locknut held immovable using a wrench, tighten the left front fork adjuster assembly locknut. Torque - left front fork adjust...

  • Page 79

    Periodic maintenance 2-57 periodic maintenance procedures right front fork • check the position of the right front fork spring preload adjuster [a] so that it can be installed in the original posi- tion. • turn [b] the right front fork spring preload adjuster to the softest position. • unscrew the t...

  • Page 80

    2-58 periodic maintenance periodic maintenance procedures • insert the compression shaft [a] and screw the extension rod [b]. • set the other side compression shaft same process. • screw the extension rods [a] into the base [b]. • install the nuts [a]. • screw in the nuts until the piston rod nut co...

  • Page 81

    Periodic maintenance 2-59 periodic maintenance procedures • unscrew the piston rod nut [a]. • remove the spring guide [b] and fork spring [c]. • hold the right front fork tube [a] upside down over a clean container [b] and drain the oil. Note ○ pump the right front fork outer tube and piston rod [c]...

  • Page 82

    2-60 periodic maintenance periodic maintenance procedures • install the spring guide. • install the piston rod nut [a] with the unthread side down. Piston rod [b] • screw the piston rod nut [a] onto the piston rod [b] as shown in the figure. 13 mm (0.51 in.) [c] • install the spring collar [a]. • in...

  • Page 83

    Periodic maintenance 2-61 periodic maintenance procedures • set the right front fork tube on the base [a] as shown in the figure. Special tool - base and extension rod: 57001-1753 • insert the compression shaft [a] and screw the extension rod [b]. • set the other side compression shaft same process....

  • Page 84

    2-62 periodic maintenance periodic maintenance procedures • turn the piston rod nut [a] counterclockwise until it con- tacts the top plug [b]. • holding the right front fork spring preload adjuster [c] with a wrench [d], tighten the piston rod nut. Torque - right front fork piston rod nut: 20 n·m (2...

  • Page 85

    Periodic maintenance 2-63 periodic maintenance procedures the torque of left front fork cylinder unit and front fork top plug are specified to 34 n·m (3.5 kgf·m, 25 ft·lb), however, when you use the top plug wrench [a], reduce the torque to 90% of the specified value [31 n·m (3.1 kgf·m, 23 ft·lb)] d...

  • Page 86

    2-64 periodic maintenance periodic maintenance procedures • using the press, push the reservoir cap [a]. • remove: circlip reservoir cap • tap [a] evenly at the holes [b] in the stopper [c] with suit- able tools [d] to free the stopper from the rear shock body. • slide up the stopper of the piston r...

  • Page 87

    Periodic maintenance 2-65 periodic maintenance procedures • hold the lower of the piston rod assembly in a vise with soft jaws or a heavy cloth. • remove the locknut [a] and discard it. Notice do not tighten the rebound damping adjuster of the piston rod. • remove the piston rod assembly from the vi...

  • Page 88

    2-66 periodic maintenance periodic maintenance procedures • remove the rebound rubber [a] out of its groove [b]. • remove: collar [c] spring holder [d] oil seal [e] • remove: oil seal [a] notice to avoid damage to the surfaces of the oil seal as- sembly body [b], cover the screwdriver [d] with the c...

  • Page 89

    Periodic maintenance 2-67 periodic maintenance procedures • inspect the piston rod sliding surface [a]. If the sliding surface is scratches or distortion, replace it. • hold the lower of the piston rod assembly in a vise with soft jaws or heavy cloth. • make the threads of the piston rod end using t...

  • Page 90

    2-68 periodic maintenance periodic maintenance procedures • install: compression side washers [a] piston [b] rebound side washers [c] stopper [d] new locknut [e] • tighten: torque - piston rod locknut: 37 n·m (3.8 kgf·m, 27 ft·lb) ○ install the piston direction as shown in the figure. Locknut side f...

  • Page 91

    Periodic maintenance 2-69 periodic maintenance procedures • push the bladder into the gas reservoir slowly until it just clears the circlip groove. Wipe out any spilled oil. • check the circlip for weakening, deformity and flaws. If necessary, replace it with a new one. Warning pressurized nitrogen ...

  • Page 92

    2-70 periodic maintenance periodic maintenance procedures • push the seal assembly into the rear shock body until it just clears the circlip groove. Replace the circlip with a new one. • fit the circlip [a] into the groove in the rear shock body [b]. • pull up the piston rod assembly [c] against the...

  • Page 93

    Periodic maintenance 2-71 periodic maintenance procedures • add the specified oil up to the damping adjuster assembly hole neck [a]. Note ○ hold the adjuster assembly hole facing up and turn the shock absorber to bleed the air from the reservoir com- pletely. • fully extend the piston rod assembly. ...

  • Page 94

    2-72 periodic maintenance periodic maintenance procedures • pump the seat down and up [a] 4 or 5 times, and inspect the smooth stroke. If the uni-trak linkage does not smooth stroke or noise is found, inspect the uni-trak linkage bearings. • push and pull on the swingarm [a] to check for wear. A sma...

  • Page 95

    Periodic maintenance 2-73 periodic maintenance procedures • unlock the clamp [a] of the number plate [b]. • remove the bolt [c]. • clear the holes [d] and remove the number plate. • remove the pad cover [e] and pad. • remove: handlebar clamp bolts [a] handlebar clamps [b] handlebar [c] • loosen the ...

  • Page 96

    2-74 periodic maintenance periodic maintenance procedures • check the steering again. If the steering is too tight or too loose, repeat the adjust- ment as mentioned above. • install the handlebar (see handlebar installation in the steering chapter). • install the handlebar pad cover [a] and pad as ...

  • Page 97

    Periodic maintenance 2-75 periodic maintenance procedures electrical system spark plug cleaning and inspection • remove the ignition coil (see ignition coil removal in the electrical system chapter). • clean the plug hole, using the compressed air [a]. • remove the spark plug [a] using a 16 mm (0.63...

  • Page 98

    2-76 periodic maintenance periodic maintenance procedures points: lubricate with grease. Clutch inner cable upper and lower ends [a] throttle inner cable upper end brake lever pivot bolt clutch lever pivot bolt brake pedal bolt cables: lubricate with rust inhibitor. Throttle inner cables clutch inne...

  • Page 99

    Periodic maintenance 2-77 periodic maintenance procedures if there are loose fasteners, retorque them to the specified torque following the specified tightening sequence. Refer to the torque and locking agent section of the general information chapter for torque specifications. For each fastener, fi...

  • Page 101: Fuel System (Dfi)

    Fuel system (dfi) 3-1 3 fuel system (dfi) table of contents exploded view........................................................................................................................ 3-4 dfi system...............................................................................................

  • Page 102

    3-2 fuel system (dfi) fuel injector removal ....................................................................................................... 3-77 fuel injector installation .................................................................................................... 3-78 fuel injector ...

  • Page 103

    Fuel system (dfi) 3-3 this page intentionally left blank..

  • Page 104

    3-4 fuel system (dfi) exploded view.

  • Page 105

    Fuel system (dfi) 3-5 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 torx screw 3.43 0.350 30.4 in·lb 2 throttle pulley cover bolts 3.4 0.35 30 in·lb 3 throttle cable mounting bolts 3.5 0.36 31 in·lb 4 throttle case mounting screws 3.8 0.38 33 in·lb 5 air cleaner element wing bolt 1.2 0...

  • Page 106

    3-6 fuel system (dfi) exploded view kx250yb model.

  • Page 107

    Fuel system (dfi) 3-7 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 water temperature sensor 12 1.2 106 in·lb 2 fuel pump bolts 9.8 1.0 87 in·lb l, s 3 gear position switch screws 2.9 0.30 26 in·lb l 4. Ecu 5. Fuel pump 6. Vehicle-down sensor 7. Ignition coil 8. Capacitor ad: apply adh...

  • Page 108

    3-8 fuel system (dfi) exploded view kx250yc model.

  • Page 109

    Fuel system (dfi) 3-9 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 water temperature sensor 12 1.2 106 in·lb 2 fuel pump bolts 9.8 1.0 87 in·lb l, s 3 gear position switch screws 2.9 0.30 26 in·lb l 4. Ecu 5. Fuel pump 6. Vehicle-down sensor 7. Ignition coil 8. Capacitor ad: apply adh...

  • Page 110

    3-10 fuel system (dfi) dfi system dfi system (kx250yb model).

  • Page 111

    Fuel system (dfi) 3-11 dfi system 1. Capacitor 2. Ecu 3. Gear position switch 4. Water temperature sensor 5. Crankshaft sensor 6. Vehicle-down sensor 7. Ignition coil 8. Fuel tank 9. Fuel pump 10. Pressure regulator 11. Intake air pressure sensor 12. Fuel injector 13. Throttle sensor 14. Intake air ...

  • Page 112

    3-12 fuel system (dfi) dfi system dfi system (kx250yc model).

  • Page 113

    Fuel system (dfi) 3-13 dfi system 1. Fuel tank 2. Fuel pump 3. Pressure regulator 4. Intake air pressure sensor 5. Downstream injector 6. Upstream injector 7. Intake air temperature sensor 8. Air cleaner housing 9. Ignition coil 10. Vehicle-down sensor 11. Crankshaft sensor 12. Throttle sensor 13. W...

  • Page 114

    3-14 fuel system (dfi) dfi system dfi system wiring diagram (kx250yb model).

  • Page 115

    Fuel system (dfi) 3-15 dfi system part names 1. Ecu 2. Fi warning indicator light harness (option) 3. Fi warning indicator light 4. Self-diagnosis terminal 5. Throttle sensor 6. Intake air pressure sensor 7. Intake air temperature sensor 8. Fuel injector 9. Water temperature sensor 10. Frame ground ...

  • Page 116

    3-16 fuel system (dfi) dfi system dfi system wiring diagram (kx250yc model).

  • Page 117

    Fuel system (dfi) 3-17 dfi system part names 1. Ecu 2. Fi warning indicator light harness (option) 3. Fi warning indicator light 4. Self-diagnosis terminal 5. Water temperature sensor 6. Throttle sensor 7. Intake air pressure sensor 8. Intake air temperature sensor 9. Downstream injector 10. Upstrea...

  • Page 118

    3-18 fuel system (dfi) dfi system terminal numbers of ecu connectors (kx250yb model) terminal names 1. Power supply to ecu 2. Vehicle-down sensor 3. Crankshaft sensor (+) 4. Gear position switch 5. Main throttle sensor 6. Intake air pressure sensor 7. Unused 8. Ground for control system 9. Crankshaf...

  • Page 119

    Fuel system (dfi) 3-19 dfi system terminal numbers of ecu connectors (kx250yc model) terminal names 1. Power supply to ecu 2. Unused 3. Unused 4. Downstream injector 5. Unused 6. Ground for ecu 7. Fi warning indicator light 8. Upstream injector 9. Unused 10. Fuel pump 11. Ignition coil 12. Power sup...

  • Page 120

    3-20 fuel system (dfi) dfi parts location ecu [a] fi warning indicator light harness connector [b] kawasaki diagnostic system connector [c] fi warning indicator light assembly [a] (option) fi warning indicator light connector [b] (option) fuel pump [a] throttle body assy [b] intake temperature senso...

  • Page 121

    Fuel system (dfi) 3-21 dfi parts location fuel injector [a] (kx250yb model) intake air pressure sensor [b] downstream injector [a] (kx250yc model) upstream injector [a] (kx250yc model).

  • Page 122

    3-22 fuel system (dfi) specifications item standard digital fuel injection system idle speed 2 050 ±50 r/min (rpm) throttle body assy: throttle valve single throttle valve bore 43 (1.69 in.) ecu: make keihin type digital memory type, with built in ic igniter, sealed with resin fuel pressure (high pr...

  • Page 123

    Fuel system (dfi) 3-23 specifications item standard gear position switch: resistance see text vehicle-down sensor: detection angle more than 55 ∼ 75° for each bank input voltage dc 4.75 ∼ 5.25 v output voltage with sensor tilted 55 ∼ 75° or more right or left: dc 3.7 ∼ 4.4 v with sensor arrow mark p...

  • Page 124

    3-24 fuel system (dfi) special tools and sealant oil pressure gauge, 5 kgf/cm²: 57001-125 fork oil level gauge: 57001-1290 vacuum gauge: 57001-1369 hand tester: 57001-1394 filler cap driver: 57001-1454 needle adapter set: 57001-1457 throttle sensor setting adapter: 57001-1538 sensor harness adapter:...

  • Page 125

    Fuel system (dfi) 3-25 special tools and sealant measuring adapter: 57001-1700 liquid gasket, tb1211: 56019-120

  • Page 126

    3-26 fuel system (dfi) dfi servicing precautions dfi servicing precautions there are a number of important precautions that should be followed servicing the dfi system. ○ connect these connectors until they click [a]. ○ never any of the dfi electrical connectors are discon- nected. The ecu memorizes...

  • Page 127

    Fuel system (dfi) 3-27 troubleshooting the dfi system outline when an abnormality in the system occurs, the condition of the problem is stored in the memory of the ecu (elec- tronic control unit). With the engine stopped and conduct a self-diagnosis inspection, the service code is indicated by the n...

  • Page 128

    3-28 fuel system (dfi) troubleshooting the dfi system ○ after measurement, remove the needle adapters and ap- ply silicone sealant to the seals [a] of the connector [b] for waterproofing. Sealant - liquid gasket, tb1211: 56019-120 • always check the connected battery condition before re- placing the...

  • Page 129

    Fuel system (dfi) 3-29 troubleshooting the dfi system ○ when checking a harness [a] for short circuit, open one end [b] and check the continuity between the other end [c] and ground [d]. If there is continuity, the harness has a short circuit to ground, and it must be repaired or re- placed. • narro...

  • Page 130

    3-30 fuel system (dfi) troubleshooting the dfi system dfi diagnosis flow chart inquiries to rider ○ each rider reacts to problems in different ways, so it is important to confirm what kind of symptoms the rider has encountered. ○ try to find out exactly what problem occurred under exactly what condi...

  • Page 131

    Fuel system (dfi) 3-31 troubleshooting the dfi system sample diagnosis sheet rider name model engine no. Frame no. Date problem occurred environment when problem occurred. Weather □ fine, □ cloudy, □ rain, □ snow, □ always, □ other: temperature □ hot, □ warm, □ cold, □ very cold, □ always problem fr...

  • Page 132

    3-32 fuel system (dfi) troubleshooting the dfi system □ spark plug loose (tighten it). □ spark plug dirty, broken, or gap maladjusted (remedy it). □ spark plug incorrect (replace it). □ knocking (fuel poor quality or incorrect). □ brake dragging. □ clutch slipping. □ engine overheating. □ engine oil...

  • Page 133

    Fuel system (dfi) 3-33 dfi system troubleshooting guide note ○ this is not an exhaustive list, giving every possible cause for each problem listed. It is meant simply as a rough guide to assist the troubleshooting for some of the more common difficulties in dfi system. ○ the ecu may be involved in t...

  • Page 134

    3-34 fuel system (dfi) dfi system troubleshooting guide symptoms or possible causes actions (chapter) intake air pressure sensor trouble inspect (see chapter 3). Water temperature sensor trouble inspect (see chapter 3). Intake air temperature sensor trouble inspect (see chapter 3). Throttle sensor t...

  • Page 135

    Fuel system (dfi) 3-35 dfi system troubleshooting guide symptoms or possible causes actions (chapter) surge: unstable fuel pressure fuel pressure regulator trouble (inspect and replace fuel pump) or kinked fuel line (inspect and replace fuel pump) (see chapter 3). Fuel injector trouble inspect (see ...

  • Page 136

    3-36 fuel system (dfi) dfi system troubleshooting guide symptoms or possible causes actions (chapter) water temperature sensor trouble inspect (see chapter 3). Intake air temperature sensor trouble inspect (see chapter 3). Throttle sensor trouble inspect (see chapter 3). Knocking: fuel poor quality ...

  • Page 137

    Fuel system (dfi) 3-37 self-diagnosis self-diagnosis outline the self-diagnosis system has three modes and can be switched to another mode by grounding the self-diagnosis terminal. User mode the ecu connected fi warning indicator light (option) goes on when dfi system and ignition system parts are f...

  • Page 138

    3-38 fuel system (dfi) self-diagnosis • connect the power supply harness (option p/no. 26011 -0246) [a] to the capacitor lead connector [b] of the main harness. • connect the power supply harness (option p/no. 26011 -0246) to the 12 v battery [c] as shown in the figure. • the fi warning indicator li...

  • Page 139

    Fuel system (dfi) 3-39 self-diagnosis self-diagnosis flow chart.

  • Page 140

    3-40 fuel system (dfi) self-diagnosis how to read service codes ○ service codes are shown by a series of long and short blinks of the fi warning indicator light as shown below. ○ read 10th digit and unit digit as the fi warning indicator light blinks. ○ when there are a number of problems, all the s...

  • Page 141

    Fuel system (dfi) 3-41 self-diagnosis service code table ser- vice code fi warning indicator light problems 11 throttle sensor malfunction, wiring open or short 12 intake air pressure sensor malfunction, wiring open or short 13 intake air temperature sensor malfunction, wiring open or short 14 water...

  • Page 142

    3-42 fuel system (dfi) self-diagnosis backups ○ the ecu takes the following measures to prevent engine damage when the dfi or the ignition system parts have troubles. Service codes parts output signal usable range or criteria backups by ecu 11 throttle sensor throttle sensor output voltage 0.58 ∼ 3....

  • Page 143

    Fuel system (dfi) 3-43 self-diagnosis note: (1) d-j method and α - n method: when the engine load is light like at idling or low speed, the ecu determines the injection quantity by calculating from the throttle vacuum (intake air pressure sen- sor output voltage) and engine speed (crankshaft sensor ...

  • Page 144

    3-44 fuel system (dfi) throttle sensor (service code 11) the throttle sensor is a rotating variable resistor that change output voltage according to throttle operating. The ecu senses this voltage change and determines fuel injection quantity, and ignition timing according to engine rpm, and throttl...

  • Page 145

    Fuel system (dfi) 3-45 throttle sensor (service code 11) • replace the o-ring [a] and throttle sensor [b]. • apply engine oil to the new o-ring and assemble it on the new throttle sensor. • engage the groove [a] in the inner rotor of the throttle sensor with the throttle shaft [b]. • insert the thro...

  • Page 146

    3-46 fuel system (dfi) throttle sensor (service code 11) • connect the throttle sensor setting adapter [a] between the harness connector [b] and throttle sensor connector [c]. Special tool - throttle sensor setting adapter: 57001 -1538 • connect a digital meter [d] to the throttle sensor setting ada...

  • Page 147

    Fuel system (dfi) 3-47 throttle sensor (service code 11) • adjust position of the sensor so that the output voltage is within the specified voltage range. Throttle sensor output voltage standard: dc 0.58 ∼ 0.62 v if the input voltage reading shows other than 5 v, calculate a valid output voltage ran...

  • Page 148

    3-48 fuel system (dfi) throttle sensor (service code 11) • disconnect the throttle sensor connector and connect the throttle sensor setting adapter [a] between these connec- tors. Harness connector [b] throttle sensor connector [c] special tool - throttle sensor setting adapter: 57001 -1538 • connec...

  • Page 149

    Fuel system (dfi) 3-49 throttle sensor (service code 11) if the reading is out of the standard, remove the ecu and check the wiring for continuity between main harness and sub harness connectors. ○ disconnect the ecu and sensor connectors. Wiring inspection ecu connector [a] ←→ throttle sensor conne...

  • Page 150

    3-50 fuel system (dfi) throttle sensor (service code 11) • measure the output voltage with the engine stopped, and with the connector joined. • connect the power supply harness (option p/no. 26011 -0246) and 12 v battery to the capacitor lead connector (see throttle sensor input voltage inspection)....

  • Page 151

    Fuel system (dfi) 3-51 throttle sensor (service code 11) throttle sensor resistance inspection • disconnect the throttle sensor connector. • connect throttle sensor setting adapter [a] to the throttle sensor. Special tool - throttle sensor setting adapter: 57001 -1538 • connect a digital meter to th...

  • Page 152

    3-52 fuel system (dfi) throttle sensor (service code 11) throttle sensor circuit (kx250yc model) 1. Ecu 2. Throttle sensor.

  • Page 153

    Fuel system (dfi) 3-53 intake air pressure sensor (service code 12) intake air pressure sensor removal notice never drop the intake air pressure sensor, espe- cially on a hard surface. Such a shock to the sensor can damage it. • remove: fuel tank (see fuel tank removal) fuel hose (see fuel hose repl...

  • Page 154

    3-54 fuel system (dfi) intake air pressure sensor (service code 12) intake air pressure sensor input voltage inspection note ○ be sure the battery is fully charged. • disconnect the intake air pressure sensor connector and connect the sensor harness adapter [a] between these connectors. Special tool...

  • Page 155

    Fuel system (dfi) 3-55 intake air pressure sensor (service code 12) if the reading is out of the standard, remove the ecu and check the wiring for continuity between main harness and sub harness connectors. ○ disconnect the ecu and sensor connectors. Wiring inspection ecu connector [a] ←→ intake air...

  • Page 156

    3-56 fuel system (dfi) intake air pressure sensor (service code 12) if the reading is within the usable range, remove the ecu and check the wiring for continuity between main harness and sub harness connectors. ○ disconnect the ecu and sensor connectors. Wiring inspection ecu connector [a] ←→ intake...

  • Page 157

    Fuel system (dfi) 3-57 intake air pressure sensor (service code 12) then pv = pl – pg for example, suppose the following data is obtained: pg = 8 cmhg (vacuum gauge reading) pl = 70 cmhg (barometer reading) vv = 3.2 v (digital meter reading) then pv = 70 – 8 = 62 cmhg (absolute) plot this pv (62 cmh...

  • Page 158

    3-58 fuel system (dfi) intake air pressure sensor (service code 12) id: idling ps: standard atmospheric pressure (absolute) pv: throttle vacuum pressure (absolute) st: standard of sensor output voltage (v) to: throttle full open ur: usable range of sensor output voltage (v) vv: intake air pressure s...

  • Page 159

    Fuel system (dfi) 3-59 intake air pressure sensor (service code 12) intake air pressure sensor circuit (kx250yb model) 1. Ecu 2. Intake air pressure sensor intake air pressure sensor circuit (kx250yc model) 1. Ecu 2. Intake air pressure sensor.

  • Page 160

    3-60 fuel system (dfi) intake air temperature sensor (service code 13) intake air temperature sensor removal/instal- lation notice never drop the intake air temperature sensor, espe- cially on a hard surface. Such a shock to the sensor can damage it. • remove the seat (see seat removal in the frame ...

  • Page 161

    Fuel system (dfi) 3-61 intake air temperature sensor (service code 13) • disconnect the capacitor lead connector [a]. • connect the power supply harness (option p/no. 26011 -0246) [a] to the capacitor lead connector [b] of the main harness. • connect the power supply harness (option p/no. 26011 -024...

  • Page 162

    3-62 fuel system (dfi) intake air temperature sensor (service code 13) if the reading is out of the standard, remove the ecu and check the wiring for continuity between main harness and sub harness connectors. ○ disconnect the ecu and sensor connectors. Wiring inspection ecu connector [a] ←→ intake ...

  • Page 163

    Fuel system (dfi) 3-63 intake air temperature sensor (service code 13) intake air temperature sensor circuit (kx250yb model) 1. Ecu 2. Intake air temperature sensor intake air temperature sensor circuit (kx250yc model) 1. Ecu 2. Intake air temperature sensor.

  • Page 164

    3-64 fuel system (dfi) water temperature sensor (service code 14) water temperature sensor removal/installation notice never drop the water temperature sensor, espe- cially on a hard surface. Such a shock to the sensor can damage it. • drain the coolant (see coolant draining in the cooling system ch...

  • Page 165

    Fuel system (dfi) 3-65 water temperature sensor (service code 14) • connect the power supply harness (option p/no. 26011 -0246) [a] to the capacitor lead connector [b] of the main harness. • connect the power supply harness (option p/no. 26011 -0246) to the 12 v battery [c] as shown. • measure the o...

  • Page 166

    3-66 fuel system (dfi) water temperature sensor (service code 14) water temperature sensor inspection • remove the water temperature sensor (see water tem- perature sensor removal/installation). • suspend the sensor [a] in a container of machine oil so that the heat-sensitive portion and threaded po...

  • Page 167

    Fuel system (dfi) 3-67 water temperature sensor (service code 14) water temperature sensor circuit (kx250yc model) 1. Ecu 2. Water temperature sensor.

  • Page 168

    3-68 fuel system (dfi) crankshaft sensor (service code 21) the crankshaft sensor has no power source, and when the engine stops, the crankshaft sensor generates no sig- nals. Crankshaft sensor removal/installation • refer to the starter coil removal/installation in the elec- trical system chapter. C...

  • Page 169

    Fuel system (dfi) 3-69 crankshaft sensor (service code 21) crankshaft sensor circuit 1. Ecu 2. Crankshaft sensor.

  • Page 170

    3-70 fuel system (dfi) gear position switch (service code 25) gear position switch removal • remove: left radiator shroud (see radiator removal in the cool- ing system chapter) shift pedal (external shift mechanism removal in the crankshaft/transmission chapter) gear position switch connector [a] • ...

  • Page 171

    Fuel system (dfi) 3-71 gear position switch (service code 25) gear position switch inspection note ○ be sure the transmission mechanism is good condition. • remove the left radiator shroud (see radiator shroud re- moval in the frame chapter). • disconnect the gear position switch lead connector [a]....

  • Page 172

    3-72 fuel system (dfi) gear position switch (service code 25) gear position switch circuit 1. Ecu 2. Frame ground 3. Gear position switch.

  • Page 173

    Fuel system (dfi) 3-73 vehicle-down sensor (service code 31) when the motorcycle is down, the engine stops according to the condition of the below table. Engine speed time engine condition 2 500 rpm or less after 30 seconds stop 2 500 rpm or more after 3 seconds stop when the vehicle-down sensor is ...

  • Page 174

    3-74 fuel system (dfi) vehicle-down sensor (service code 31) • disconnect the capacitor lead connector [a]. • connect the power supply harness (option p/no. 26011 -0246) [a] to the capacitor lead connector [b] of the main harness. • connect the power supply harness (option p/no. 26011 -0246) to the ...

  • Page 175

    Fuel system (dfi) 3-75 vehicle-down sensor (service code 31) vehicle-down sensor output voltage inspection • remove the vehicle-down sensor. ○ remove the vehicle-down sensor, and connect the mea- suring adapter [a]. Special tool - measuring adapter: 57001-1700 main harness [b] vehicle-down sensor [c...

  • Page 176

    3-76 fuel system (dfi) vehicle-down sensor (service code 31) if the reading is within the standard, remove the ecu and check the wiring for continuity between main harness side connectors. ○ disconnect the ecu and sensor connectors. Wiring inspection ecu connector [a] ←→ vehicle-down sensor connecto...

  • Page 177

    Fuel system (dfi) 3-77 fuel injector (service code 41) note ○ service code 41 indicates downstream injector in the kx250yc model. Notice never drop the fuel injector, especially on a hard surface. Such a shock to the injector can damage it. Fuel injector removal • remove: rear frame (see rear frame ...

  • Page 178

    3-78 fuel system (dfi) fuel injector (service code 41) fuel injector installation • replace the dust seal [b] with a new one. • apply silicone grease or engine oil to the o-ring [a] and dust seal. • assemble the delivery pipe [a] and the fuel injector [b]. • fit the projections [a] on the delivery p...

  • Page 179

    Fuel system (dfi) 3-79 fuel injector (service code 41) fuel injector audible inspection • remove: left radiator shroud (see radiator removal in the cool- ing system chapter) • start the engine, and let it idle. • apply the tip of a screwdriver [a] to the fuel injector. Put the grip end into your ear...

  • Page 180

    3-80 fuel system (dfi) fuel injector (service code 41) fuel injector power supply voltage inspection note ○ be sure the battery is fully charged. • disconnect the injector connector and connect the mea- suring adapter [a] between these connector. Main harness [b] fuel injector [c] special tool - mea...

  • Page 181

    Fuel system (dfi) 3-81 fuel injector (service code 41) fuel injector output voltage inspection note ○ be sure the battery is fully charged. • remove the ecu (see ecu removal). ○ do not disconnect the ecu connector. • connect the power supply harness (option p/no. 26011 -0246) and 12 v battery to the...

  • Page 182

    3-82 fuel system (dfi) fuel injector (service code 41) injector fuel line inspection • remove: fuel tank (see fuel tank removal) fuel hose (see fuel hose replacement in the periodic maintenance chapter) ○ be sure to place a piece of cloth around the fuel outlet pipe of fuel pump and delivery pipe of...

  • Page 183

    Fuel system (dfi) 3-83 fuel injector (service code 41) fuel injector circuit (kx250yb model) 1. Ecu 2. Fuel injector 3. Frame ground 4. Capacitor fuel injector circuit (kx250yc model) 1. Ecu 2. Downstream injector 3. Frame ground 4. Capacitor.

  • Page 184

    3-84 fuel system (dfi) upstream injector (service code 42) (kx250yc model) notice never drop the upstream injector, especially on a hard surface. Such a shock to the upstream injector can damage it. Upstream injector removal • remove: rear frame (see rear frame removal in the frame chapter) • remove...

  • Page 185

    Fuel system (dfi) 3-85 upstream injector (service code 42) (kx250yc model) • fit the projection [a] on the delivery pipe to the hollow [b] of the air cleaner housing. ○ face the connector side to front side. • apply a non-permanent locking agent to the threads of the delivery joint bolt [a]. • tight...

  • Page 186

    3-86 fuel system (dfi) upstream injector (service code 42) (kx250yc model) upstream injector power supply voltage inspection note ○ be sure the battery is fully charged. • disconnect the upstream injector connector and connect the measuring adapter [a] between these connector. Main harness [b] upstr...

  • Page 187

    Fuel system (dfi) 3-87 upstream injector (service code 42) (kx250yc model) upstream injector output voltage inspection note ○ be sure the battery is fully charged. • remove the ecu (see ecu removal). ○ do not disconnect the ecu connector. • connect the power supply harness (option p/no. 26011 -0246)...

  • Page 188

    3-88 fuel system (dfi) upstream injector (service code 42) (kx250yc model) upstream injector fuel line inspection • remove: fuel hose (see rear frame removal in the frame chap- ter) ○ be sure to place a piece of cloth around the delivery pipe of air cleaner housing. • check the upstream injector fue...

  • Page 189

    Fuel system (dfi) 3-89 upstream injector (service code 42) (kx250yc model) upstream injector circuit 1. Ecu 2. Upstream injector 3. Frame ground 4. Capacitor.

  • Page 190

    3-90 fuel system (dfi) fuel pump (service code 46) fuel pump removal warning gasoline is extremely flammable and can be ex- plosive under certain conditions. Always stop the engine and do not smoke. Make sure the area is well-ventilated and free from any source of flame or sparks; this includes any ...

  • Page 191

    Fuel system (dfi) 3-91 fuel pump (service code 46) • install the fuel pump [a] to the fuel tank. • apply a non-permanent locking agent to the threads of the fuel pump bolts. • gradually tighten the fuel pump bolts evenly following the specified tightening sequence [1 ∼ 6]. Torque - fuel pump bolts: ...

  • Page 192

    3-92 fuel system (dfi) fuel pump (service code 46) fuel pump operating voltage inspection note ○ be sure the battery is fully charged. • remove the left radiator shroud (see radiator removal in the cooling system chapter). • disconnect the fuel pump lead connector and connect the harness adapter [a]...

  • Page 193

    Fuel system (dfi) 3-93 fuel pump (service code 46) pressure regulator removal ○ the pressure regulator [a] is built into the fuel pump and can not be removed. Fuel filter cleaning ○ the fuel filter [a] is built into the pump and can not be cleaned or checked. If the fuel filter is suspected of clogg...

  • Page 194

    3-94 fuel system (dfi) fuel pump (service code 46) fuel pump circuit (kx250yc model) 1. Ecu 2. Frame ground 3. Fuel pump 4. Capacitor.

  • Page 195

    Fuel system (dfi) 3-95 ignition coil (service code 51) ignition coil removal/installation • refer to the ignition coil removal/installation in the elec- trical system chapter. Ignition coil input voltage inspection • refer to the ignition coil peak voltage inspection in the electrical system chapter...

  • Page 196

    3-96 fuel system (dfi) ecu ecu identification ○ most countries have their own regulations, so each ecu has different characteristic. So, do not confuse ecu with each other and use only the ecu for your model. Other- wise, the motorcycle cannot clear the regulation. Ecu identification (kx250yb model)...

  • Page 197

    Fuel system (dfi) 3-97 ecu ecu installation • install the ecu [b] to the rubber protector [a]. • insert the slits [a] of the rubber protector to the air cleaner housing bracket. • connect the ecu connector [b]. Ecu power supply inspection • remove the number plate (see front fork removal in the susp...

  • Page 198

    3-98 fuel system (dfi) ecu • disconnect the ecu connector [a]. • set the hand tester [b] to the × 1 Ω range and check the following wiring for continuity. Special tool - hand tester: 57001-1394 ecu grounding inspection ecu connector ←→ capacitor connector [c] kx250yb model [d] bk/w lead [e] (ecu ter...

  • Page 199

    Fuel system (dfi) 3-99 ecu • connect a digital meter [a] to the connector [b] with the needle adapter set. Kx250yb model [c] kx250yc model [d] special tool - needle adapter set: 57001-1457 ecu power supply inspection connections: digital meter (+) → terminal 1 (r/w lead) digital meter (–) → battery ...

  • Page 200

    3-100 fuel system (dfi) fuel line fuel pressure inspection note ○ be sure the battery is fully charged. • remove: radiator shroud (see radiator removal in the cooling system chapter) fuel tank (see fuel tank removal) fuel hose (see fuel injector removal) ○ be sure to place a piece of cloth around th...

  • Page 201

    Fuel system (dfi) 3-101 fuel line • connect the power supply harness (option p/no. 26011 -0246) [a] to the capacitor lead connector [b] of the main harness. • connect the power supply harness (option p/no. 26011 -0246) to the 12 v battery [c] as shown. Note ○ inspect the fuel leakage from the connec...

  • Page 202

    3-102 fuel system (dfi) fuel line fuel flow rate inspection warning gasoline is extremely flammable and can be ex- plosive under certain conditions. Always stop the engine and do not smoke. Make sure the area is well-ventilated and free from any source of flame or sparks; this includes any appliance...

  • Page 203

    Fuel system (dfi) 3-103 fuel line • disconnect the capacitor lead connector [a]. • connect the power supply harness (option p/no. 26011 -0246) [a] to the capacitor lead connector [b] of the main harness. • connect the power supply harness (option p/no. 26011 -0246) to the 12 v battery [c] as shown t...

  • Page 204

    3-104 fuel system (dfi) throttle grip and cable if the throttle grip has excessive free play due to cable stretch or misadjustment, there will be a delay in throttle re- sponse. Also, the throttle valve may not open fully at full throttle. On the other hand, if the throttle grip has no play, the thr...

  • Page 205

    Fuel system (dfi) 3-105 throttle grip and cable • loosen the mounting bolts [a]. • remove the cables [b] from the throttle body assy. • free the tips [c] from the pulley. • pull out the cables from the frame. • lubricate the cable. • apply grease to the tips of the cables. • install the throttle cab...

  • Page 206

    3-106 fuel system (dfi) throttle body assy idle speed inspection • refer to the idle speed inspection in the periodic main- tenance chapter. Throttle bore cleaning • refer to the throttle body cleaning in the periodic main- tenance chapter. Throttle body assy removal warning gasoline is extremely fl...

  • Page 207

    Fuel system (dfi) 3-107 throttle body assy throttle body assy installation • install the throttle body assy so that fit the projection [b] on throttle body assy and groove [a] of the throttle body holder. • install the removed parts (see appropriate chapters). • disconnect the capacitor lead connect...

  • Page 208

    3-108 fuel system (dfi) throttle body assy • pull out the injector [a] from the delivery pipe [b]. Note ○ do not damage the insertion portions of the injector when they are pulled out from the delivery pipe. Notice never drop the fuel injector, especially on a hard surface. Such a shock to the injec...

  • Page 209

    Fuel system (dfi) 3-109 throttle body assy • replace the o-ring [a] of delivery pipe [b] with a new one. • apply silicone grease or engine oil to the o-ring. • install the delivery pipe in the joint [c], and tighten the screw securely. • replace the dust seal [b] with a new one. • apply silicone gre...

  • Page 210

    3-110 fuel system (dfi) throttle body assy • install the plate so that fit the hollow [a] on the plate and projection [b] on the throttle body assy. • install the vacuum hose [c]. • tighten the plate mounting screws securely..

  • Page 211

    Fuel system (dfi) 3-111 air cleaner air cleaner housing removal • remove the rear frame (see rear frame removal in the frame chapter). • remove the air cleaner housing bolts [a]. • take the air cleaner housing off the rear frame. Air cleaner housing installation • assemble the air cleaner housing (s...

  • Page 212

    3-112 fuel system (dfi) fuel tank fuel tank removal warning gasoline is extremely flammable and can be ex- plosive under certain conditions. Always stop the engine and do not smoke. Make sure the area is well-ventilated and free from any source of flame or sparks; this includes any appliance with a ...

  • Page 213

    Fuel system (dfi) 3-113 fuel tank • pull [b] the fuel hose joint [a] out of the fuel outlet pipe. Warning fuel is flammable and explosive under certain con- ditions and can cause severe burns. Be prepared for fuel spillage; any spilled fuel must be completely wiped up immediately. When the fuel hose...

  • Page 214

    3-114 fuel system (dfi) fuel tank • push and pull [b] the hose joint [a] back and forth more than two times, and make sure it is locked and does not come off. Warning leaking fuel can cause a fire or explosion resulting in serious burns. Make sure the hose joint is in- stalled correctly on the deliv...

  • Page 215: Cooling System

    Cooling system 4-1 4 cooling system table of contents exploded view........................................................................................................................ 4-2 specifications ................................................................................................

  • Page 216

    4-2 cooling system exploded view.

  • Page 217

    Cooling system 4-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 radiator shroud bolts 9.8 1.0 87 in·lb 2 radiator mounting bolts 9.8 1.0 87 in·lb 3 radiator screen bolts 9.8 1.0 87 in·lb 4 water hose clamp screws 3.0 0.31 27 in·lb 5 water pipe bolt 9.8 1.0 87 in·lb 6 water pump cover ...

  • Page 218

    4-4 cooling system specifications item standard coolant type permanent type antifreeze (soft water and ethylene glycol plus corrosion and rust inhibitor chemicals for aluminum engines and radiators) color green mixed ratio soft water 50%, coolant 50% freezing point –35°c (–31°f) total amount 1.2 l (...

  • Page 219

    Cooling system 4-5 special tool bearing driver set: 57001-1129.

  • Page 220

    4-6 cooling system coolant coolant level inspection • refer to the coolant level inspection in the periodic main- tenance chapter. Coolant deterioration inspection • refer to the coolant deterioration inspection in the peri- odic maintenance chapter. Coolant draining warning coolant can be extremely...

  • Page 221

    Cooling system 4-7 coolant coolant filling notice use coolant containing corrosion inhibitors made specifically for aluminum engines and radiators in accordance with the instruction of the manufac- ture’s. Soft or distilled water must be used with the antifreeze (see below for antifreeze) in the coo...

  • Page 222

    4-8 cooling system coolant cooling system pressure testing notice during pressure testing, do not exceed the pres- sure for which the system is designed to work. The maximum pressure is 123 kpa (1.25 kgf/cm², 18 psi). • remove the radiator cap, and install a cooling system pressure tester [a] and ad...

  • Page 223

    Cooling system 4-9 water pump water pump cover removal • remove the oil filter (see oil filter change in the periodic maintenance chapter). ○ drain the engine oil from the water pump cover. • drain the coolant (see coolant draining). • unscrew the water pipe bolt [a], and disconnect the water pipe [...

  • Page 224

    4-10 cooling system water pump • replace the water pipe o-ring [a] with a new one. • apply soap and water solution to the new o-ring. • insert the water pipe [b] straightly into the hole of the wa- ter pump cover. • tighten: torque - water pipe bolt: 9.8 n·m (1.0 kgf·m, 87 in·lb) • install the oil f...

  • Page 225

    Cooling system 4-11 water pump • check the drainage outlet passage [a] at the bottom of the right engine cover for coolant leaks. If the oil seal is damaged, the coolant leaks through the seal and drains through the passage. Replace the oil seals. Water pump gear removal • remove: water pump cover (...

  • Page 226

    4-12 cooling system water pump • insert a bar [a] into the water pump shaft hole from the inside. • remove the oil seal [b] by tapping [c] evenly around the seal lips. Oil seal and bearing installation notice if the oil seal or ball bearing is removed, replace all of them with new ones at the same t...

  • Page 227

    Cooling system 4-13 radiator radiator removal • drain the coolant (see coolant draining). • remove: radiator shroud bolts [a] (both sides) radiator shroud [b] (both sides) • remove the capacitor [a] (see capacitor removal in the electrical system chapter). • loosen: water hose clamp screws [b] • pul...

  • Page 228

    4-14 cooling system radiator radiator installation • install: radiators water hoses washers clutch cable clamps [a] (left side) • tighten: torque - radiator mounting bolts: 9.8 n·m (1.0 kgf·m, 87 in·lb) water hose clamp screws: 3.0 n·m (0.31 kgf·m, 27 in·lb) • run the joint hose, over flow hose and ...

  • Page 229

    Cooling system 4-15 radiator radiator cap inspection • check the top and bottom valve seals [a] of the radiator cap, and the condition of the valve spring [b]. If any one of them shows visible damage, replace the cap. • wet the top and bottom valve seals with water or coolant to prevent pressure lea...

  • Page 231: Engine Top End

    Engine top end 5-1 5 engine top end table of contents exploded view................................... 5-2 specifications .................................... 5-6 special tools and sealant ................. 5-9 cylinder head cover ......................... 5-12 cylinder head cover removal .... 5-12 ...

  • Page 232

    5-2 engine top end exploded view.

  • Page 233

    Engine top end 5-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 auto-decompressor bolt 12 1.2 106 in·lb 2 cylinder head cover bolts 9.8 1.0 87 in·lb 3 camshaft cap bolts 9.8 1.0 87 in·lb s, mo 4 cylinder head bolts (m10) 49 5.0 36 s, mo 5 cylinder head bolts (m6) 12 1.2 106 in·lb s 6 ...

  • Page 234

    5-4 engine top end exploded view.

  • Page 235

    Engine top end 5-5 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 exhaust pipe cover bolts 12 1.2 106 in·lb 2 exhaust pipe holder nuts 15 1.5 11 s 3 muffler mounting bolts 21 2.1 15 s 4 muffler clamp bolt 11 1.1 97 in·lb s l: apply a non-permanent locking agent. Lg: apply liquid gasket....

  • Page 236

    5-6 engine top end specifications item standard service limit camshafts cam height: exhaust 33.943 ∼ 34.057 mm (1.3363 ∼ 1.3408 in.) 33.84 mm (1.332 in.) intake 35.243 ∼ 35.357 mm (1.3875 ∼ 1.3920 in.) 35.14 mm (1.383 in.) camshaft journal/cap clearance 0.020 ∼ 0.062 mm (0.0008 ∼ 0.0024 in.) 0.15 mm...

  • Page 237

    Engine top end 5-7 specifications item standard service limit valve seat surface: outside diameter: exhaust 24.6 ∼ 24.8 mm (0.969 ∼ 0.976 in.) – – – intake 30.6 ∼ 30.8 mm (1.205 ∼ 1.213 in.) – – – width: exhaust 0.5 ∼ 1.0 mm (0.02 ∼ 0.04 in.) – – – intake 0.5 ∼ 1.0 mm (0.02 ∼ 0.04 in.) – – – valve s...

  • Page 238

    5-8 engine top end specifications cam height cam height [a] camshaft runout valve stem diameter valve stem diameter [a] 45° [b] valve stem bend dial gauge [a].

  • Page 239

    Engine top end 5-9 special tools and sealant compression gauge, 20 kgf/cm²: 57001-221 valve spring compressor assembly: 57001-241 piston ring compressor grip: 57001-1095 piston ring compressor belt, 67 ∼ 79: 57001-1097 valve seat cutter, 45° - 27.5: 57001-1114 valve seat cutter, 45° - 32: 57001-1115...

  • Page 240

    5-10 engine top end special tools and sealant compression gauge adapter, m10 × 1.0: 57001-1317 valve seat cutter, 60° - 25: 57001-1328 valve seat cutter holder, 4.5: 57001-1330 valve guide arbor, 4.5: 57001-1331 valve guide reamer, 4.5: 57001-1333 valve seat cutter, 60° - 33: 57001-1334 filler cap d...

  • Page 241

    Engine top end 5-11 special tools and sealant valve guide driver attachment, f: 57001-1722 liquid gasket, tb1216b: 92104-1064.

  • Page 242

    5-12 engine top end cylinder head cover cylinder head cover removal • remove: fuel tank (see fuel tank removal in the fuel system chapter) spark plug cap [a] cylinder head cover bolts [b] cylinder head cover [c] • remove the cylinder head cover gasket [a]. Cylinder head cover installation • replace ...

  • Page 243

    Engine top end 5-13 cylinder head cover • install the cylinder head cover bolt washers [a] with the metal side upwards. • tighten: torque - cylinder head cover bolts [b]: 9.8 n·m (1.0 kgf·m, 87 in·lb) • install the removed parts (see appropriate chapters)..

  • Page 244

    5-14 engine top end camshaft chain tensioner camshaft chain tensioner removal notice this is a non-return type camshaft chain tensioner. The push rod does not return to its original position once it moves out to take up camshaft chain slack. Observe all the rules listed below: when removing the tens...

  • Page 245

    Engine top end 5-15 camshafts camshaft removal • remove: cylinder head cover (see cylinder head cover re- moval) capacitor (see capacitor removal in the electrical sys- tem chapter) timing inspection cap [a] flywheel nut cap [b] special tool - filler cap driver: 57001-1454 • bring the piston to the ...

  • Page 246

    5-16 engine top end camshafts • remove: bolt [a] auto-decompressor [b] spring [c] camshaft installation • when installing the spring [a] on the auto-decompressor [b], put the spring end [c] onto the outside coil as shown in the figure. • install the auto-decompressor [a] in the exhaust camshaft. • t...

  • Page 247

    Engine top end 5-17 camshafts • bring the crankshaft to the tdc. ○ place a wrench over the flywheel nut [a] and turn it coun- terclockwise to align the tdc mark [b] with the center of the groove [c] of the inspection hole. • engage the camshaft chain with the camshaft sprockets. ○ align the timing m...

  • Page 248

    5-18 engine top end camshafts • install the dowel pins [a] and positioning rings [b]. • apply molybdenum disulfide oil to the threads and seating surface of the camshaft cap bolts. • tighten all camshaft cap bolts evenly and lightly, and then tighten them with specified torque. ○ follow the numbers ...

  • Page 249

    Engine top end 5-19 camshafts camshaft chain installation • engage the camshaft chain to the crankshaft. • install the lower camshaft chain guide. • tighten: torque - lower camshaft chain guide bolt: 9.8 n·m (1.0 kgf·m, 87 in·lb) • install: flywheel magneto (see flywheel magneto installation in the ...

  • Page 250

    5-20 engine top end camshafts cam wear inspection • remove the camshaft (see camshaft removal). • measure the height [a] of each cam with a micrometer. Cam height standard: exhaust 33.943 ∼ 34.057 mm (1.3363 ∼ 1.3408 in.) intake 35.234 ∼ 35.357 mm (1.3875 ∼ 1.3920 in.) service limit: exhaust 33.84 m...

  • Page 251

    Engine top end 5-21 cylinder head cylinder compression measurement • warm up the engine thoroughly. • stop the engine. • remove: fuel tank (see fuel tank removal in the fuel system chapter) spark plug (see spark plug cleaning and inspection in the periodic maintenance chapter) • attach the compressi...

  • Page 252

    5-22 engine top end cylinder head cylinder head removal • remove: fuel tank (see fuel tank removal in the fuel system (dfi) chapter) camshaft chain tensioner (see camshaft chain ten- sioner removal) cylinder head cover (see cylinder head cover re- moval) camshaft (see camshaft removal) exhaust pipe ...

  • Page 253

    Engine top end 5-23 cylinder head cylinder head installation • install the front camshaft chain guide. ○ fit the projection [a] in the groove [b] of the cylinder. ○ insert the guide end [c] into the recess of the crankcase securely. ○ in this figure, the magneto cover and flywheel has been removed f...

  • Page 254

    5-24 engine top end cylinder head cylinder head warp inspection • refer to the cylinder head warp inspection in the peri- odic maintenance chapter..

  • Page 255

    Engine top end 5-25 valves valve clearance inspection • refer to the valve clearance inspection in the periodic maintenance chapter. Valve clearance adjustment • refer to the valve clearance adjustment in the periodic maintenance chapter. Valve removal • remove the cylinder head (see cylinder head r...

  • Page 256

    5-26 engine top end valves valve installation • visually inspect the valve surface. If the surface is damaged, replace the valve. • replace the oil seal [a] with a new one. • apply a thin coat of molybdenum disulfide grease to the valve stem [b] and install the valve. • check to make sure that the v...

  • Page 257

    Engine top end 5-27 valves • hammer lightly on the valve guide arbor [a] to remove the guide. Special tool - valve guide arbor, 4.5: 57001-1331 valve guide installation • apply a thin coat of engine oil to the outer surface of the valve guide. • heat the area around the valve guide up to 120 ∼ 150°c...

  • Page 258

    5-28 engine top end valves • repeat the measurement in a direction at a 90° angle to the first measurement. Note ○ the reading is greater than the actual valve/valve guide clearance because the measurement is taken outside of the guide. Valve/valve guide clearance (wobble method) standard: exhaust 0...

  • Page 259

    Engine top end 5-29 valves valve seat repair • for the instructions on how to use the valve seat cutter [a], follow the operation manual provided by the tool man- ufacturer. Special tools - valve seat cutter holder, 4.5 [b]: 57001 -1330 valve seat cutter holder bar: 57001-1128 exhaust: valve seat cu...

  • Page 260

    5-30 engine top end valves marks stamped on the cutter: the marks stamped on the back of the cutter [a] represent the following. 60° ........................... Cutter angle [b] 37.5 ....................... Cutter outer diameter [c] repair operating procedures • clean the seat area carefully. • coat...

  • Page 261

    Engine top end 5-31 valves if the outside diameter [a] of the seating surface is too large, make the 32° [b] grind described below. If the outside diameter of the seating surface is within the specified range, measure the seat width as described be- low. • grind the seat at a 32° angle until the sea...

  • Page 262

    5-32 engine top end valves valve seat repair.

  • Page 263

    Engine top end 5-33 cylinder and piston cylinder removal • remove: cylinder head (see cylinder head removal) front camshaft chain guide [a] cylinder bolt [b] • tap lightly up with a plastic hammer to separate the cylin- der [c] from the crankcase. • remove the cylinder base gasket. Piston removal • ...

  • Page 264

    5-34 engine top end cylinder and piston • install the top ring [a] so that the "r" mark [b] faces up. Note ○ if a new piston or cylinder is used, check piston to cylin- der clearance (see piston/cylinder clearance inspec- tion in the periodic maintenance chapter), and use new piston rings. • apply e...

  • Page 265

    Engine top end 5-35 cylinder and piston • apply engine oil to the cylinder bore and the piston side wall. • install the cylinder while compressing the piston rings with your fingers or the special tool [a]. ○ upturn the chamfering side of the belt. Special tools - piston ring compressor grip: 57001-...

  • Page 266

    5-36 engine top end cylinder and piston piston ring groove width inspection • measure the groove width at several points around the piston with a vernier caliper. Piston ring groove width standard: top 0.83 ∼ 0.85 mm (0.0327 ∼ 0.335 in.) service limit: top 0.93 mm (0.037 in.) if any of the groove wi...

  • Page 267

    Engine top end 5-37 cylinder and piston piston, piston pin, connecting rod wear inspection • visually inspect the snap ring [a] still fitted in place. If the ring shows weakness or deformation, replace the ring. Also if the pin hole groove shows excessive wear, replace the piston. • measure the diam...

  • Page 268

    5-38 engine top end throttle body holder throttle body holder installation • install: throttle body holder throttle body holder clamp ○ turn the mark [a] to the throttle body assy. ○ turn the screw head [b] to the engine left side. • fit the projection [a] of the cylinder head and the recess [b] of ...

  • Page 269

    Engine top end 5-39 muffler warning the muffler can become extremely hot during nor- mal operation and cause severe burns. Do not re- move the muffler while it is hot. Muffler body removal • remove the right side cover (see side cover removal in the frame chapter). • loosen the muffler clamp bolt [a...

  • Page 271: Clutch

    Clutch 6-1 6 clutch table of contents exploded view........................................................................................................................ 6-2 specifications ................................................................................................................

  • Page 272

    6-2 clutch exploded view.

  • Page 273

    Clutch 6-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 clutch cover bolts 9.8 1.0 87 in·lb 2 right engine cover bolts 9.8 1.0 87 in·lb 3 clutch spring bolts 9.0 0.92 80 in·lb 4 clutch hub nut 98 10 72 r 5 oil filler plug 5.0 0.51 44 in·lb cl: apply cable lubricant. Eo: apply engine o...

  • Page 274

    6-4 clutch specifications item standard service limit clutch lever clutch lever free play 8 ∼ 13 mm (0.3 ∼ 0.5 in.) – – – clutch friction plate thickness 2.72 ∼ 2.88 mm (0.107 ∼ 0.113 in.) 2.5 mm (0.10 in.) friction plate warp 0.15 mm (0.0059 in.) or less 0.3 mm (0.012 in.) steel plate warp 0.15 mm ...

  • Page 275

    Clutch 6-5 special tools inside circlip pliers: 57001-143 bearing driver set: 57001-1129 clutch holder: 57001-1243.

  • Page 276

    6-6 clutch clutch lever and cable due to friction plate wear and clutch cable stretch over a long period of use, the clutch must be adjusted in accor- dance with the periodic maintenance chart. Warning the engine and exhaust system get extremely hot during normal operation and can cause serious burn...

  • Page 277

    Clutch 6-7 clutch lever and cable • align the slit [a] of the adjusting nut to the slit [b] of the lever. • free the clutch cable upper end. • take the cable off the cable holder [a]. • take the cable lower end [b] off the clutch release lever [c]. Notice do not remove the clutch release shaft unles...

  • Page 278

    6-8 clutch clutch cover and right engine cover clutch cover removal • drain the engine oil (see engine oil change in the peri- odic maintenance chapter). • remove: brake pedal bolt [a] brake pedal return spring [b] • remove the clutch cover bolts [a] and take off the clutch cover. Clutch cover insta...

  • Page 279

    Clutch 6-9 clutch cover and right engine cover • remove: bolt [a] right engine guard [b] • remove: water pump cover (see water pump cover removal in the cooling system chapter) clutch cover bolts [a] right engine cover bolts [b] right engine cover [c] right engine cover installation • apply a grease...

  • Page 280

    6-10 clutch clutch cover and right engine cover • pour: engine oil (see engine oil change in the periodic main- tenance chapter) coolant (see coolant filling in the cooling system chap- ter) • check the rear brake effectiveness (see brakes section in the periodic maintenance chapter). Oil seal insta...

  • Page 281

    Clutch 6-11 clutch clutch removal • drain the engine oil (see engine oil change in the peri- odic maintenance chapter). • remove: clutch cover (see clutch cover removal) clutch spring bolts [a] springs clutch pressure plate [b] • remove: push rod holder assembly [a] friction plates [b] steel plates ...

  • Page 282

    6-12 clutch clutch • install the clutch housing [a]. ○ turn the kick idle gear and the oil pump idle gear with suitable tool [b] to fit in the clutch housing. • install: thrust washer [a] clutch hub [b] • hold the clutch hub with the clutch holder [a]. Special tool - clutch holder: 57001-1243 • inst...

  • Page 283

    Clutch 6-13 clutch • if a clutch part was replaced, install the standard adjusting washer (1.5 mm thickness) [a] of the push rod holder as- sembly, and check the release lever position as explained later procedure. • install the clutch pressure plate and clutch springs. • tighten the clutch spring b...

  • Page 284

    6-14 clutch clutch release shaft removal • remove: clutch (see clutch removal) clutch cable upper end (see clutch cable removal) • remove the tips [a] of the clutch cable. • pull out the release shaft assembly [b]. Release shaft installation • apply engine oil to the bearings [a]. • replace the oil ...

  • Page 285

    Clutch 6-15 clutch friction plate/clutch housing clearance inspection • measure the clearance between the tangs [a] on the fric- tion plate and the fingers [b] of the clutch housing. ○ if this clearance is excessive, the clutch will be noisy. Friction plate/clutch housing clearance standard: 0.04 ∼ ...

  • Page 287: Engine Lubrication System

    Engine lubrication system 7-1 7 engine lubrication system table of contents exploded view........................................................................................................................ 7-2 engine oil flow chart....................................................................

  • Page 288

    7-2 engine lubrication system exploded view.

  • Page 289

    Engine lubrication system 7-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 breather fitting 15 1.5 11 l 2 oil pump mounting bolts 7.0 0.71 62 in·lb l 3 oil pump idle gear shaft screws 5.9 0.60 52 in·lb l 4 oil filter cap bolts 9.8 1.0 87 in·lb 5 piston oil nozzle 2.9 0.30 26 in·lb 6 e...

  • Page 290

    7-4 engine lubrication system engine oil flow chart.

  • Page 291

    Engine lubrication system 7-5 engine oil flow chart 1. Oil screen (scavenge) 2. Oil screen (feed) 3. Oil pump (scavenge) 4. Oil pump (feed) 5. Oil filter 6. Oil shower to transmission 7. Piston oil nozzle 8. Kick starter idle gear 9. Breather hose a: crank room oil b: transmission room oil c: blowby...

  • Page 292

    7-6 engine lubrication system specifications item standard engine oil grade castrol “power1 r4 racing” 5w-40 or api sg, sh, sj, sl or sm with jaso ma, ma1 or ma2 viscosity sae 10w-30, 10w-40, or 10w-50 capacity oil change - when filter is not removed 0.75 l (0.79 us qt) oil change - when filter is r...

  • Page 293

    Engine lubrication system 7-7 special tools oil pressure gauge, 5 kgf/cm²: 57001-125 outside circlip pliers: 57001-144 oil pressure gauge adapter, m6 × 1.0: 57001-1664.

  • Page 294

    7-8 engine lubrication system engine oil and oil filter warning vehicle operation with insufficient, deteriorated, or contaminated engine oil will cause accelerated wear and may result in engine seizure, accident, and injury. Check the oil level before each use and change the oil and filter accordin...

  • Page 295

    Engine lubrication system 7-9 engine oil and oil filter oil filter replacement • refer to the oil filter replacement in the periodic main- tenance chapter. Oil screen cleaning and inspection oil screen (feed) • remove the engine (see engine removal in the engine removal/installation chapter). • sepa...

  • Page 296

    7-10 engine lubrication system engine oil and oil filter oil screen (scavenge) • remove the magneto cover (see magneto cover re- moval in the electrical system chapter). • remove the oil screen (scavenge) [a]. • clean the oil screen with a high-flash point solvent and remove any particles stuck to i...

  • Page 297

    Engine lubrication system 7-11 oil pump oil pump removal • drain: engine oil (see engine oil change in the periodic main- tenance chapter) coolant (see coolant draining in the cooling system chapter) • remove: brake pedal (see brake pedal removal in the brakes chapter) kick pedal (see kick pedal rem...

  • Page 298

    7-12 engine lubrication system oil pump • disassemble the oil pump assembly. Pins [a] oil pump cover [b] inner [c] and outer [d] rotors (feed) oil pump body [e] oil pump gear [f] oil pump installation • apply molybdenum disulfide grease to the shaft of the oil pump gear. • apply engine oil to the in...

  • Page 299

    Engine lubrication system 7-13 oil pump • apply a non-permanent locking agent to the oil pump mounting bolts. • tighten: torque - oil pump mounting bolts: 7.0 n·m (0.71 kgf·m, 62 in·lb) • apply engine oil to the shaft of the oil pump idle gear. • install the oil pump idle gear. • turn the oil pump i...

  • Page 300

    7-14 engine lubrication system oil pressure oil pressure measurement • remove water pump cover bolt. • install the oil pressure gauge adapter [a] to the water pump cover. Special tool - oil pressure gauge adapter, m6 × 1.0: 57001-1664 • attach the oil pressure gauge [a]. Special tool - oil pressure ...

  • Page 301: Engine Removal/installation

    Engine removal/installation 8-1 8 engine removal/installation table of contents exploded view........................................................................................................................ 8-2 special tools .......................................................................

  • Page 302

    8-2 engine removal/installation exploded view.

  • Page 303

    Engine removal/installation 8-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 upper engine mounting bolts 49 5.0 36 s 2 upper engine bracket bolts 29 3.0 21 s 3 middle engine mounting nut 49 5.0 36 r, s 4 middle engine bracket nuts 29 3.0 21 r, s 5 lower engine mounting nut 49 5.0 36 r...

  • Page 304

    8-4 engine removal/installation special tools jack: 57001-1238 attachment jack: 57001-1252 jack attachment: 57001-1608.

  • Page 305

    Engine removal/installation 8-5 engine removal/installation engine removal • remove the engine guards. • place the jack under the frame to support the motorcycle. Special tools - jack: 57001-1238 jack attachment :57001-1252 or 57001-1608 warning when the swingarm pivot shaft is removed the swingarm ...

  • Page 306

    8-6 engine removal/installation engine removal/installation • remove: rear frame (see rear frame removal in the frame chapter) exhaust pipe (see exhaust pipe removal in the engine top end chapter) fuel tank (see fuel tank removal in the fuel system (dfi) chapter) vehicle-down sensor (vehicle-down se...

  • Page 307

    Engine removal/installation 8-7 engine removal/installation • remove the following parts on both sides: upper engine bracket bolts [a] upper engine mounting bolts [b] and nuts upper engine brackets [c] • remove: middle engine bracket bolts [a] and nuts middle engine mounting bolt [b] and nut middle ...

  • Page 308

    8-8 engine removal/installation engine removal/installation kx250yc • install the washers [a] as shown in the figure. • insert the swingarm pivot shaft. • install all engine brackets, bolts and nuts temporarily. ○ insert the following bolts from left side: middle engine mounting bolt [a] middle engi...

  • Page 309

    Engine removal/installation 8-9 engine removal/installation • install the removed parts (see appropriate chapters). • run the cables, hoses, and leads according to the cable, wire and hose routing section in the appendix chapter. • fill: engine oil (see engine oil change in the periodic main- tenanc...

  • Page 311: Crankshaft/transmission

    Crankshaft/transmission 9-1 9 crankshaft/transmission table of contents exploded view........................................................................................................................ 9-2 specifications ..............................................................................

  • Page 312

    9-2 crankshaft/transmission exploded view.

  • Page 313

    Crankshaft/transmission 9-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 crankcase bolts (l = 50 mm) 9.8 1.0 87 in·lb s 2 crankcase bolts (l = 60 mm) 9.8 1.0 87 in·lb s 3 crankcase bolts (l = 65 mm) 9.8 1.0 87 in·lb s 4 crankcase bolts (l = 70 mm) 9.8 1.0 87 in·lb s 5 crankcase bearin...

  • Page 314

    9-4 crankshaft/transmission exploded view.

  • Page 315

    Crankshaft/transmission 9-5 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 kick pedal bolt 25 2.5 18 l 2 kick ratchet guide bolt 8.8 0.90 78 in·lb l 3 ratchet plate bolt 9.8 1.0 87 in·lb l, s 4 ratchet plate screw 15 1.5 11 l, s 5 shift drum cam bolt 24 2.4 18 l 6 gear positioning lever...

  • Page 316

    9-6 crankshaft/transmission specifications item standard service limit crankshaft, connecting rod connecting rod big end: radial clearance 0.002 ∼ 0.014 mm (0.00008 ∼ 0.00055 in.) 0.06 mm (0.0024 in.) side clearance 0.25 ∼ 0.35 mm (0.0098 ∼ 0.0138 in.) 0.6 mm (0.02 in.) crankshaft runout tir 0.03 mm...

  • Page 317

    Crankshaft/transmission 9-7 special tools & sealant bearing puller: 57001-135 bearing puller adapter: 57001-136 outside circlip pliers: 57001-144 bearing driver set: 57001-1129 crankshaft jig: 57001-1174 crankcase splitting tool assembly: 57001-1362 gear holder, m2.0: 57001-1557 liquid gasket, tb121...

  • Page 318

    9-8 crankshaft/transmission crankcase crankcase disassembly • remove the engine from the frame (see engine removal in the engine removal/installation chapter). • set the engine on clean surface while parts are being re- moved. • remove: cylinder head cover (see cylinder head cover re- moval in the e...

  • Page 319

    Crankshaft/transmission 9-9 crankcase • position the connecting rod in bdc. • install the jig [a] between the crankshaft flywheels. Special tool - crankshaft jig: 57001-1174 • attach the crankcase splitting tool [a] to the left crankcase. ○ adjust the gap with suitable collars or nuts [b] as shown i...

  • Page 320

    9-10 crankshaft/transmission crankcase • remove the reed valve [a] from the left crankcase half. ○ unscrew the screws [b] and remove the guide [c]. Crankcase assembly notice right and left crankcase halves are machined at the factory in the assembled state, so if replaced, they must be replaced as a...

  • Page 321

    Crankshaft/transmission 9-11 crankcase • press the new drive shaft bearing [a] so that the sealed side [b] faces outside of the engine. • press the new output shaft bearing [c] so that the stepped side [d] faces inside of the engine. Special tool - bearing driver set: 57001-1129 • install the left c...

  • Page 322

    9-12 crankshaft/transmission crankcase • install the reed valve [a] and guide [b] as shown in the figure. • tighten: torque - reed valve screws [c]: 7.0 n·m (0.71 kgf·m, 62 in·lb) right crankcase • press the new crankshaft bearing [a] and new drive shaft bearing [b] until they bottom out. Special to...

  • Page 323

    Crankshaft/transmission 9-13 crankcase • install the right crankcase bearing retainers. ○ the right crankcase bearing retainers are larger than left ones. • apply a non-permanent locking agent to the crankcase bearing retainer screws [a]. • tighten: torque - crankcase bearing retainer screws: 15 n·m...

  • Page 324

    9-14 crankshaft/transmission crankcase • apply liquid gasket to the mating surface [a] of the left crankshaft half. ○ using a high-flash point solvent, clean off any oil or dirt that may be on the liquid gasket coating area. Dry them with a clean cloth. Sealant - liquid gasket, tb1216: 92104-1063 no...

  • Page 325

    Crankshaft/transmission 9-15 crankshaft crankshaft removal • disassemble the crankcase (see crankcase disassem- bly). • remove the transmission shafts (see transmission shaft removal). • using a hand press, remove the crankshaft from the right crankcase. If the bearing stay on the crankshaft when sp...

  • Page 326

    9-16 crankshaft/transmission crankshaft • carefully align the oil passage hole in the right flywheel [a] with the one in the crankpin [b] at rebuilding of the crankshaft as shown in the figure. • reassemble the crankshaft according to the standard tol- erances in specifications. ○ connecting rod ben...

  • Page 327

    Crankshaft/transmission 9-17 crankshaft crankshaft runout inspection • set the crankshaft in a flywheel alignment jig or on v blocks, and place a dial gauge as shown and turn the crankshaft slowly. The maximum difference in gauge reading is the crankshaft runout. 8 mm (0.3 in.) [a] crankshaft runout...

  • Page 328

    9-18 crankshaft/transmission crankshaft connecting rod bend inspection • remove the connecting rod. • select an arbor [a] of the same diameter as the connect- ing rod big end, and insert it through the connecting rod big end. • select an arbor [b] of the same diameter as the piston pin and more than...

  • Page 329

    Crankshaft/transmission 9-19 transmission transmission shaft removal • disassemble the crankcase halves (see crankcase dis- assembly). • pull out the shift rods [a], and take off the shift forks [b]. • remove the shift drum [c]. • pull out the drive shaft [d] and output shaft [e] together. Transmiss...

  • Page 330

    9-20 crankshaft/transmission transmission • install the oil screen (feed) [a] as shown in the figure. Longer outcrop of pipe [b] right crankcase [c] • assembly the crankcase (see crankcase assembly). Transmission shaft disassembly • remove the transmission shafts (see transmission shaft removal). • ...

  • Page 331

    Crankshaft/transmission 9-21 transmission 1. Circlip (small) 2. Toothed washer 3. Circlip (large) 4. Ball bearing (left crankcase, one side sealed) 5. 2nd gear (16t) 6. Needle bearing 7. 4th gear (17t) 8. 3rd gear (18t) 9. 5th gear (22t) 10. Drive shaft (1st gear, 14t) 11. Ball bearing (right crankc...

  • Page 332

    9-22 crankshaft/transmission transmission shift fork/gear groove wear inspection • measure the thickness [a] of the shift fork ears, and mea- sure the width [b] of the gear grooves (with which the fork engages). Shift fork ear thickness standard: 4.9 ∼ 5.0 mm (0.193 ∼ 0.197 in.) service limit: 4.8 m...

  • Page 333

    Crankshaft/transmission 9-23 bearings/oil seals bearing replacement notice do not remove the ball bearings unless it is neces- sary. Removal may damage them. • remove the ball bearing and/or needle bearing outer race using a press or suitable bearing remover. Note ○ in the absence of the above menti...

  • Page 334

    9-24 crankshaft/transmission bearings/oil seals • check the needle bearing. ○ the rollers in a needle bearing normally wear very little, and wear is difficult to measure. Instead of measuring, inspect the bearing for abrasion, color change, or other damage. If there is any doubt as to the condition ...

  • Page 335

    Crankshaft/transmission 9-25 primary gear primary gear removal • remove: right engine cover (see right engine cover removal in the clutch chapter) clutch (see clutch removal in the clutch chapter) • temporarily install the clutch housing [a], clutch hub [b] and clutch hub nut [c]. • hold the primary...

  • Page 336

    9-26 crankshaft/transmission external shift mechanism external shift mechanism removal • remove: shift pedal bolt [a] shift pedal [b] • remove: right engine cover (see right engine cover removal in the clutch chapter) clutch (see clutch removal in the clutch chapter) • pull out the shift shaft [a], ...

  • Page 337

    Crankshaft/transmission 9-27 external shift mechanism external shift mechanism installation • install: pin [a] spring [b] collar [c] gear positioning lever [d] washer [e] • tighten: torque - gear positioning lever nut: 8.8 n·m (0.90 kgf·m, 78 in·lb) • hold the gear positioning lever [a] with the sui...

  • Page 338

    9-28 crankshaft/transmission external shift mechanism • apply grease to the oil seal lips [a] and shift shaft splines [b]. • insert the shift shaft [a] as shown in the figure. ○ take care not to damage the oil seal when inserting the shift shaft. • install: clutch (see clutch removal in the clutch c...

  • Page 339

    Crankshaft/transmission 9-29 external shift mechanism • check the gear positioning lever [a] and its spring [b] for cracks or distortion. If the lever or spring is damaged in any way, replace them. • visually inspect the shift drum cam [a]. If it is badly worn or if it shows any damage, replace it..

  • Page 340

    9-30 crankshaft/transmission kickstarter kick pedal removal • remove: kick pedal bolt [a] kick pedal assy [b] kick pedal installation • install the kick pedal assy. ○ put the pedal end [a] near the cylinder head mating sur- face [b]. • apply a non-permanent locking agent to the kick pedal bolt. • ti...

  • Page 341

    Crankshaft/transmission 9-31 kickstarter • remove the bolts [a], and take off the ratchet guide [b]. Kick shaft installation • apply a non-permanent locking agent to the kick ratchet guide bolt. • install the ratchet guide [a], and tighten the bolt. Torque - kick ratchet guide bolt [b]: 8.8 n·m (0.9...

  • Page 343: Wheels/tires

    Wheels/tires 10-1 10 wheels/tires table of contents exploded view........................................................................................................................ 10-2 specifications .................................................................................................

  • Page 344

    10-2 wheels/tires exploded view.

  • Page 345

    Wheels/tires 10-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 spoke nipples not less than 2.2 not less than 0.22 not less than 19 in·lb 2 front axle nut 78 8.0 58 3 front axle clamp bolts 20 2.0 15 al 4 rear axle nut 108 11.0 80 al: tighten the two clamp bolts alternately two times t...

  • Page 346

    10-4 wheels/tires specifications item standard service limit wheels (rims) rim size: front 21 × 1.60 – – – rear 19 × 1.85 – – – rim runout: axial tir 1.0 mm (0.04 in.) or less tir 2.0 mm (0.08 in.) radial tir 1.0 mm (0.04 in.) or less tir 2.0 mm (0.08 in.) axle runout/100 mm (3.94 in.) tir 0.1 mm (0...

  • Page 347

    Wheels/tires 10-5 special tools inside circlip pliers: 57001-143 rim protector: 57001-1063 bead breaker assembly: 57001-1072 bearing driver set: 57001-1129 jack: 57001-1238 attachment jack: 57001-1252 bearing remover head, 20 × 22: 57001-1293 bearing remover head, 25 × 28: 57001-1346 bearing remover...

  • Page 348

    10-6 wheels/tires wheels (rims) front wheel removal • using the jack under the frame, and stabilize the motor- cycle. Special tools - jack: 57001-1238 jack attachment: 57001-1252 or 57001 -1608 • loosen the axle clamp bolts [a] on both sides. • unscrew the axle nut [b]. • using a commercially availa...

  • Page 349

    Wheels/tires 10-7 wheels (rims) • pump the front fork up and down [a] 4 or 5 times to align both fork positions. Note ○ put a block [b] in front of the wheel to stop moving. ○ do not apply the front brake. • tighten: torque - front axle clamp bolts (right): 20 n·m (2.0 kgf·m, 15 ft·lb) note ○ tighte...

  • Page 350

    10-8 wheels/tires wheels (rims) rear wheel installation • fit the groove [a] of the caliper holder and the swingarm rib [b]. • apply high-temperature grease to the oil seal lips. • install the caps and collars to the hub on both sides. ○ fit the projection [a] and the groove [b]. • install the rear ...

  • Page 351

    Wheels/tires 10-9 wheels (rims) • adjust the drive chain slack (see drive chain slack in- spection in the periodic maintenance chapter). • check the rear brake for good braking power and no brake drag. Warning after servicing, it takes several applications of the brake pedal before the brake pads co...

  • Page 352

    10-10 wheels/tires wheels (rims) axle inspection • visually inspect the front and rear axle for damages. If the axle is damaged or bent, replace it. • place the axle on v blocks that are 100 mm (3.94 in.) [a] apart, and set a dial gauge [b] on the axle at a point halfway between the blocks. • turn [...

  • Page 353

    Wheels/tires 10-11 tires air pressure inspection/adjustment • refer to the air pressure inspection/adjustment in the pe- riodic maintenance chapter. Tire removal notice do not lay the wheel directly on the ground with the disc facing down. This can damage or warp the disc. Place blocks under the whe...

  • Page 354

    10-12 wheels/tires tires • break the beads away from both sides of the rim with the bead breaker [a]. Special tool - bead breaker assembly: 57001-1072 • step on the tire opposite valve stem, pry the tire off the rim with the tire iron [a]. ○ protect the rim with rim protectors [b]. Special tools - r...

  • Page 355

    Wheels/tires 10-13 tires • align the valve stem [a] and the tire balance mark [b] (the chalk mark made during removal; see tire removal). ○ the new tire is no marked. • insert the valve stem into the rim, and screw the nut on loosely. • fit the rim protectors and use tire irons to install the tire b...

  • Page 356

    10-14 wheels/tires hub bearing front hub bearing removal • remove front wheel (see front wheel removal) grease seals [a] • use the bearing remover to remove the hub bearings [a]. Notice do not lay the wheel on the ground with the disc facing down. This can damage or warp the disc. Place wooden block...

  • Page 357

    Wheels/tires 10-15 hub bearing • using a suitable bar [a], tap the around of the bearing inner race evenly to remove the bearings [b]. Hub bearing installation • before installing the hub bearings, blow any dirt or foreign particles out of the hub with compressed air to prevent contamination of the ...

  • Page 358

    10-16 wheels/tires hub bearing hub bearing inspection since the hub bearings are made to extremely close tol- erances, the clearance can not normally be measured. Note ○ do not remove any bearings for inspection. If any bear- ings are removed, they will need to be replaced with new ones. • turn each...

  • Page 359: Final Drive

    Final drive 11-1 11 final drive table of contents exploded view........................................................................................................................ 11-2 specifications ...................................................................................................

  • Page 360

    11-2 final drive exploded view.

  • Page 361

    Final drive 11-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks engine sprocket cover bolts (kx250yb model) 4.9 0.50 43 in·lb 1 engine sprocket cover bolts (kx250yc model) 9.8 1.0 87 in·lb 2 rear sprocket nuts 34 3.5 25 r 3. Kx250yb model 4. Kx250yc model g: apply grease. Ho: apply heavy ...

  • Page 362

    11-4 final drive specifications item standard service limit drive chain chain slack 52 ∼ 58 mm (2.0 ∼ 2.3 in.) – – – chain 20-link length 317.5 ∼ 318.2 mm (12.50 ∼ 12.53 in.) 323 mm (12.7 in.) standard chain: make: daido – – – type: did 520dma4 – – – link: 114 links – – – sprocket rear sprocket warp...

  • Page 363

    Final drive 11-5 special tool outside circlip pliers: 57001-144.

  • Page 364

    11-6 final drive drive chain drive chain slack inspection • refer to the drive chain slack inspection in the periodic maintenance chapter. Drive chain slack adjustment • refer to the drive chain slack adjustment in the periodic maintenance chapter. Wheel alignment inspection • check that the notch [...

  • Page 365

    Final drive 11-7 drive chain • install the link plate [a] so that the mark faces out. • install the clip [b] so that the closed end [c] of the "u" pointed in the direction of chain rotation [d]. • adjust the drive chain slack (see drive chain slack ad- justment in the periodic maintenance chapter)..

  • Page 366

    11-8 final drive sprockets engine sprocket removal • remove: engine sprocket cover bolts [a] engine sprocket cover [b] drive chain guide [c] • remove the circlip [a], and take off the engine sprocket [b] together with the drive chain. ○ using the thin blade driver [c] as shown in the figure when rem...

  • Page 367

    Final drive 11-9 sprockets rear sprocket removal • remove the rear wheel (see rear wheel removal in the wheels/tires chapter). Notice do not lay the wheel on the ground with the disc facing down. This can damage or warp the disc. Place blocks under the wheel so that the disc does not touch the groun...

  • Page 369: Brakes

    Brakes 12-1 12 brakes table of contents exploded view........................................................................................................................ 12-2 specifications .............................................................................................................

  • Page 370

    12-2 brakes exploded view.

  • Page 371

    Brakes 12-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 front brake reservoir cap screws 1.5 0.15 13 in·lb 2 front master cylinder clamp bolts 8.8 0.90 78 in·lb s 3 brake lever pivot bolt 5.9 0.60 52 in·lb si 4 brake lever pivot bolt locknut 5.9 0.60 52 in·lb 5 brake hose banjo bolts...

  • Page 372

    12-4 brakes exploded view.

  • Page 373

    Brakes 12-5 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 rear brake reservoir cap screws 1.5 0.15 13 in·lb 2 rear master cylinder mounting bolts 9.8 1.0 87 in·lb 3 brake hose banjo bolts 25 2.5 18 4 rear master cylinder push rod locknut 17 1.7 13 5 brake pedal bolt 25 2.5 18 l, g 6 re...

  • Page 374

    12-6 brakes specifications item standard service limit brake lever lever free play adjustable (to suit rider) – – – brake fluid grade: front dot3 or dot4 – – – rear dot3 or dot4 – – – brake pads lining thickness: front 4.0 mm (0.16 in.) 1 mm (0.04 in.) rear 6.4 mm (0.25 in.) 1 mm (0.04 in.) brake di...

  • Page 375

    Brakes 12-7 special tools jack: 57001-1238 attachment jack: 57001-1252 jack attachment: 57001-1608.

  • Page 376

    12-8 brakes brake lever, brake pedal brake lever play adjustment • refer to the brake lever and pedal adjustment in the periodic maintenance chapter. Brake pedal position adjustment • refer to the brake lever and pedal adjustment in the periodic maintenance chapter. Brake pedal removal • remove: cot...

  • Page 377

    Brakes 12-9 brake lever, brake pedal • replace the o-rings [a] with new ones. • apply grease to the o-rings and shaft portion [b] of the brake pedal bolt. • apply a non-premanent locking agent to the thread of the brake pedal bolt. • install the brake pedal [c]. ○ install the washer [d] inside the p...

  • Page 378

    12-10 brakes brake fluid warning when working with the disc brake, observe the pre- cautions listed below. 1. Never reuse old brake fluid. 2. Do not use fluid from a container that has been left unsealed or that has been open for a long time. 3. Do not mix two types and brands of fluid for use in th...

  • Page 379

    Brakes 12-11 brake fluid brake line bleeding the brake fluid has a very low compression coefficient so that almost all the movement of the brake lever or pedal is transmitted directly to the caliper for braking action. Air, however, is easily compressed. When air enters the brake lines, brake lever ...

  • Page 380

    12-12 brakes brake fluid • bleed the brake line and the caliper as follows: ○ repeat this operation until no more air can be seen com- ing out into the plastic hose. 1. Pump the brake lever until it becomes hard, and apply the brake and hold it [a]. 2. Quickly open and close [b] the bleed valve whil...

  • Page 381

    Brakes 12-13 caliper caliper removal front brake • loosen the brake pad pin [a] before the caliper [b] re- moval if the caliper is to be disassembled. • loosen the banjo bolt [c] so as not to spill brake fluid. Note ○ if the caliper is to be disassembled after removal and compressed air is not avail...

  • Page 382

    12-14 brakes caliper caliper installation • install the brake pad if it was removed (see brake pad installation). Front brake • install the caliper and tighten the bolts. Torque - front caliper mounting bolts: 25 n·m (2.5 kgf·m, 18 ft·lb) rear brake • install the rear wheel and caliper (see rear whe...

  • Page 383

    Brakes 12-15 caliper fluid seal damage inspection the fluid seals [a] around the piston maintains the proper pad/disc clearance. If this seal is not in good condition, pad wear will increase, and constant pad drag on the disc will raise brake and brake fluid temperature. • replace the fluid seals un...

  • Page 384

    12-16 brakes caliper caliper piston and cylinder damage • visually inspect the pistons [a] and cylinder surfaces. Replace the caliper if the cylinder and piston are badly scores or rusty. [b] front caliper [c] rear caliper caliper holder shaft wear the caliper body must slide smoothly on the caliper...

  • Page 385

    Brakes 12-17 brake pad brake pad removal front brake • remove the pad pin [a]. • take off the piston side pad [b]. • push the caliper holder toward the piston, and then re- move another pad [c]. Rear brake • remove: pad pin plug [a] • remove the pad pin [a]. • take off the piston side pad [b]. • pus...

  • Page 386

    12-18 brakes brake pad • tighten the brake pad pin. Torque - brake pad pin: 17 n·m (1.7 kgf·m, 13 ft·lb) rear brake pad pin plug: 2.5 n·m (0.25 kgf·m, 22 in·lb) • check the brake for good braking power, no brake drag, and no fluid leakage. Warning after servicing, it takes several applications of th...

  • Page 387

    Brakes 12-19 master cylinder notice brake fluid quickly ruins painted or plastic sur- faces; any spilled fluid should be completely washed up immediately. Front master cylinder removal • remove the banjo bolt [a] to disconnect the brake hose upper end [b] from the master cylinder [c]. ○ when removin...

  • Page 388

    12-20 brakes master cylinder • the master cylinder clamp must be installed with the ar- row mark [a] upward. • tighten the upper clamp bolt [b] first, and then the lower clamp bolt [c]. ○ there will be a gap at the lower mating surface of the clamp after tightening. Torque - front master cylinder cl...

  • Page 389

    Brakes 12-21 master cylinder rear master cylinder installation • install the brake hose. ○ replace the washers [a] are on each side of hose fitting [b] with new ones. • tighten: torque - brake hose banjo bolt: 25 n·m (2.5 kgf·m, 18 ft·lb) • install the rear master cylinder. • tighten: torque - rear ...

  • Page 390

    12-22 brakes master cylinder master cylinder inspection (visual inspection) • disassemble the front and rear master cylinders. • check that there are no scratches, rust or pitting on the inner wall of each master cylinder [a] and on the outside of each piston [b]. If a master cylinder or piston show...

  • Page 391

    Brakes 12-23 brake disk brake disc removal • remove the wheels (see front/rear wheel removal in the wheels/tires chapter). • unscrew the mounting bolts, and take off the disc. Brake disc installation • install the brake disc on the wheel so that the marked side [a] faces out. • apply a non-permanent...

  • Page 392

    12-24 brakes brake hose brake hose removal/installation • refer to the brake hose replacement in the periodic maintenance chapter. Brake hose inspection • refer to the brake hoses and connections inspection in the periodic maintenance chapter..

  • Page 393: Suspension

    Suspension 13-1 13 suspension table of contents exploded view........................................................................................................................ 13-2 specifications .....................................................................................................

  • Page 394

    13-2 suspension exploded view.

  • Page 395

    Suspension 13-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 left front fork cylinder unit 34 3.5 25 2 front fork clamp bolts (lower) 23 2.3 17 al 3 front fork clamp bolts (upper) 23 2.3 17 al, l 4 left front fork adjuster assembly locknut 22 2.2 16 5 left front fork base valve assemb...

  • Page 396

    13-4 suspension exploded view.

  • Page 397

    Suspension 13-5 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 rear shock absorber mounting nut (upper) 39 4.0 29 r 2 rear shock absorber mounting nut (lower) 34 3.5 25 r 3 tie-rod mounting nuts 59 6.0 44 g, r 4 swingarm pivot shaft nut 98 10 72 r 5 rocker arm pivot nut 59 6.0 44 g, r 6...

  • Page 398

    13-6 suspension specifications item standard service limit front fork air pressure atmospheric pressure – – – rebound damping adjustment (left fork only) (from the seated position adjuster turned fully clockwise) 10 clicks counterclockwise (eur, br) 12 clicks counterclockwise (kx250yb) (eur, br) 8 c...

  • Page 399

    Suspension 13-7 specifications item standard service limit spring preload adjustment (adjustable range) (adjusting nut position from the center of the mounting hole upper) 129.8 mm (5.11 in.) (kx250yb) 129.5 mm (5.10 in.) (kx250yc) (eur, br) 131.3 mm (5.17 in.) (kx250yb) (eur, br) 128 mm (5.04 in.) ...

  • Page 400

    13-8 suspension special tools oil seal & bearing remover: 57001-1058 hook wrench r37.5, r42: 57001-1101 bearing driver set: 57001-1129 jack: 57001-1238 attachment jack: 57001-1252 bearing remover shaft, 9: 57001-1265 bearing remover head, 15 × 17: 57001-1267 hook wrench t=3.2 r37: 57001-1539 jack at...

  • Page 401

    Suspension 13-9 special tools fork cylinder holder, hex 17: 57001-1754.

  • Page 402

    13-10 suspension front fork air pressure the standard air pressure in the front fork legs is atmo- spheric pressure. Air pressure in the fork legs increase with normal use, so the fork action stiffens during operation. Re- lease air pressure prior to each race through the pressure relief screw. • pl...

  • Page 403

    Suspension 13-11 front fork seated positions, adjuster turned fully clockwise [a]. Compression damping adjuster setting standard: 7 clicks [b] (kx250yb) 8 clicks (kx250yc) (eur, br) 9 clicks counterclockwise (kx250yb) (eur, br) 14 clicks counterclockwise (kx250yc) softer (counterclockwise) [c] harde...

  • Page 404

    13-12 suspension front fork spring preload adjustment (right fork only) • place the jack under the frame so that the front wheel is raises off the ground. Special tools - jack: 57001-1238 jack attachment: 57001-1252 or 57001 -1608 • turn the adjuster [a] on the right front fork top plug [b] with the...

  • Page 405

    Suspension 13-13 front fork • unlock the clamp [a] of the number plate [b]. • remove the bolt [c]. • clear the holes [d] and remove the number plate. • loosen the front fork clamp bolts (upper [a] and lower [b]). • pull out the front fork downward with a twisting motion [a]. Front fork installation ...

  • Page 406

    13-14 suspension front fork front fork disassembly • drain the fork oil (see front fork oil change in the peri- odic maintenance chapter). Left front fork • unscrew the left front fork adjuster assembly locknut [a]. • wrap the piston rod end [b] with a vinyl tape. • push out the piston rod [c]. Righ...

  • Page 407

    Suspension 13-15 front fork ○ remove the retaining ring [a] from the outer tube. ○ grasp the tubes and stroke the inner tube up and down [a] several times. The shock to fork seal separates the inner tube from the outer tube. • remove: bushings [a] washer [b] oil seal [c] retaining ring [d] dust seal...

  • Page 408

    13-16 suspension front fork • when assembling the new outer tube bushings, washer and new oil seal [a], hold the oil seal against the new one, and tap the oil seal with the fork oil seal driver [b] until it stops. Special tool - fork oil seal driver, 47: 57001-1662 • install the retaining ring to th...

  • Page 409

    Suspension 13-17 front fork inner tube inspection • visually inspect the inner tube [a], repair any damage. • nick or rust damage can sometimes be repaired by using a wet-stone to remove sharp edges or raised areas which cause seal damage. If the damage is not repairable, replace the inner tube. Sin...

  • Page 410

    13-18 suspension rear shock absorber to suit to various riding conditions, the spring preload of the shock absorber can be adjusted or the spring can be replaced with an optional one. Also the damping force can be adjusted easily so changing oil viscosity unnecessary. Notice do not force the rebound...

  • Page 411

    Suspension 13-19 rear shock absorber • adjust the high speed compression damping, turn the high speed compression damping adjuster with a 14 mm wrench. If the damping feels too soft or too stiff, adjust it in accor- dance with the following table. Seated position: adjuster turned fully clockwise [a]...

  • Page 412

    13-20 suspension rear shock absorber • using the hook wrenches [a], loosen the locknut [b]. Special tools - hook wrench r37.5, r42: 57001-1101 hook wrench t=3.2 r37: 57001-1539 • using the hook wrench [a], turn the adjusting nut [b] as required. Turning the adjusting nut downward marks the spring ac...

  • Page 413

    Suspension 13-21 rear shock absorber rear shock absorber removal • remove: seat (see seat removal in the frame chapter) side covers (see side cover removal in the frame chapter) muffler body (see muffler body removal in the engine top end chapter) rear frame (see rear frame removal in the frame chap...

  • Page 414

    13-22 suspension rear shock absorber • hold the upper end of the rear shock absorber in a vise with soft jaws [a] or a heavy cloth. • using the hook wrenches [b], loosen the locknut [c] and turn the adjusting nut all way up. Special tools - hook wrench r37.5, r42: 57001-1101 hook wrench t=3.2 r37: 5...

  • Page 415

    Suspension 13-23 swingarm swingarm removal • remove: rear wheel (see rear wheel removal in the wheels/tires chapter) rear flap (see rear flap removal in the frame chap- ter) brake pedal bolt [a] return spring [b] • remove: bolts [a] chain guide plate [b] chain guide [c] brake hose clamps [d] • put t...

  • Page 416

    13-24 suspension swingarm swingarm installation • apply plenty of grease to the inside of the needle bear- ings, sleeves, and oil seals. • apply a non-permanent locking agent to the chain slipper mounting screws. • install the chain slipper, and tighten the screws. • replace with new ones: swingarm ...

  • Page 417

    Suspension 13-25 swingarm drive chain guide, guide roller, chain slipper wear inspection • visually inspect the drive chain guide [a] and replace it if excessively worn or damaged. • visually inspect the chain slipper [a] on the swingarm and replace it if excessively worn or damaged. • visually insp...

  • Page 418

    13-26 suspension tie-rod, rocker arm tie-rod removal • using the jack under the frame, raise the rear wheel off the ground. Special tools - jack: 57001-1238 jack attachment: 57001-1252 or 57001 -1608 • remove: nut [a] lower chain guide roller [b] • remove: tie-rod rear mounting bolt and nut [a] tie-...

  • Page 419

    Suspension 13-27 tie-rod, rocker arm • remove: rear shock absorber bolt and nut [a] (lower) rocker arm pivot bolt and nut [b] rocker arm [c] rocker arm installation • replace with new ones: rear shock absorber mounting nut (lower) rocker arm pivot nut tie-rod mounting nut • apply plenty of grease to...

  • Page 420

    13-28 suspension tie-rod, rocker arm tie-rod and rocker arm bearing installation • replace the needle bearing, grease seals and oil seals with new ones. • apply plenty of grease to the oil seals, grease seals and needle bearings. Note ○ install the bearings so that the marked side faces out. ○ insta...

  • Page 421

    Suspension 13-29 tie-rod, rocker arm needle bearing inspection notice do not remove the bearings for inspection. Re- moval may damage them. • inspect the needle bearings installed in the rocker arm. ○ the needle bearing normally wear very little, and wear is difficult to measure. Instead of measurin...

  • Page 422

    13-30 suspension uni-trak maintenance uni-trak linkage inspection • refer to the swingarm and uni-trak linkage inspection in the periodic maintenance chapter. Tie-rod and rocker arm sleeve wear inspection • pull out the sleeves [a] of the tie-rod and rocker arm. • measure the outside diameter of the...

  • Page 423: Steering

    Steering 14-1 14 steering table of contents exploded view........................................................................................................................ 14-2 special tools ..........................................................................................................

  • Page 424

    14-2 steering exploded view.

  • Page 425

    Steering 14-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 handlebar clamp bolts 25 2.5 18 al 2 steering stem head nut 98 10 72 3 front fork clamp bolts (upper ) 23 2.3 17 al, l 4 steering stem nut 4.9 0.50 43 in·lb 5 handle holder nuts 34 3.5 25 r 6 front fork clamp bolts (lower) 23 ...

  • Page 426

    14-4 steering special tools bearing puller: 57001-135 steering stem bearing driver: 57001-137 bearing puller adapter: 57001-317 steering stem bearing driver adapter, 34.5: 57001-1074 head pipe outer race press shaft: 57001-1075 head pipe outer race driver, 51.5: 57001-1076 head pipe outer race drive...

  • Page 427

    Steering 14-5 steering steering inspection • refer to the steering inspection in the periodic mainte- nance chapter. Steering adjustment • refer to the steering adjustment in the periodic mainte- nance chapter. Steering stem, stem bearing removal • unhook the clamp [a] of the number plate [b]. • rem...

  • Page 428

    14-6 steering steering • take off the upper stem bearing inner race (tapered roller bearing) [a]. • drive out the bearing outer races from the head pipe. ○ remove the outer races pressed into the head pipe, using the head pipe outer race remover [a], and hammer the head pipe outer race remover to dr...

  • Page 429

    Steering 14-7 steering • replace the inner races with new ones. • apply grease to the lower tapered roller bearing [a], and drive it onto the stem with the steering stem bearing driver [b] and adapter [c]. Special tools - steering stem bearing driver: 57001-137 steering stem bearing driver adapter, ...

  • Page 430

    14-8 steering steering • install the removed parts (see appropriate chapters). Warning if the handlebar does not turn to the steering stop it may cause an accident resulting in injury or death. Be sure the cables, harnesses and hoses are routed properly and do not interfere with handlebar move- ment...

  • Page 431

    Steering 14-9 handlebar handlebar removal • unhook the clamp [a] of the number plate [b]. • remove the bolt [c]. • clear the holes [d] and remove the number plate. • remove the pad cover [e] and pad. • remove: clutch lever holder assembly [a] engine stop switch [b] bands [c] left handlebar grip [d] ...

  • Page 432

    14-10 steering handlebar • install the clutch lever holder assembly [a] as shown in the figure. 25° ∼ 35° [b] horizontal line of frame [c] 170 mm (6.69 in.) [d] • install the engine stop switch. • apply grease to the throttle cable upper end and clutch cable upper end. • apply 2-stroke oil to the ed...

  • Page 433

    Steering 14-11 handlebar • install the handlebar [a] on the steering stem head as follows. ○ the handlebar angle position can be adjusted to suit your preference using the gauge marks [b]. ○ position the handlebar so that the gauge marks is equal positions [c]. Bridge bar [d] • install the handlebar...

  • Page 435: Frame

    Frame 15-1 15 frame table of contents exploded view........................................................................................................................ 15-2 frame ........................................................................................................................

  • Page 436

    15-2 frame exploded view.

  • Page 437

    Frame 15-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 rear frame mounting bolts 34 3.5 25 2 footpeg bracket bolts (upper) 54 5.5 40 l g: apply grease. L: apply a non-permanent locking agent. R: replacement parts.

  • Page 438

    15-4 frame frame frame inspection • refer to the frame inspection in the periodic mainte- nance chapter. Rear frame removal • remove: seat (see seat removal) side covers (see side cover removal) muffler body (see muffler body removal in the engine top end chapter) rear fender (see rear fender remova...

  • Page 439

    Frame 15-5 frame • remove the rear frame mounting bolts [a] on both sides. • take off the rear frame [b] together with the air cleaner housing. ○ separate the air cleaner duct from the throttle body. ○ take care not to damage the frame and rear shock ab- sorber with the air cleaner duct clamp. • rem...

  • Page 440

    15-6 frame frame engine guards installation • install the engine guards as shown in the figure. Right engine guard [a] left engine guard [b] lower engine guard [c] bolts [d] collars [e] ○ fit the projection [a] of the right engine guard and hole [b] of the frame. ○ fit the left engine guard similarl...

  • Page 441

    Frame 15-7 seat seat removal • remove the side cover bolt [a] on both sides. • spread [a] the side covers lightly. • take off the seat [b] backward [c]. Seat installation • install the seat. ○ insert the hooks [a] of the seat under the flange collar [b] and brackets [c]. ○ take care not to damage th...

  • Page 442

    15-8 frame side covers side cover removal • remove the bolts [a] and take off the side cover. ○ clear the side cover tabs [b] from the air cleaner housing. Side cover installation • stick the pad [a] on the inside of the right side cover. • install the damper [b] securely. • install the side covers....

  • Page 443

    Frame 15-9 fender front fender removal • remove the bolts [a] and take off the front fender. Rear fender removal • remove the side covers (see side cover removal). • remove the bolts [a]. • remove the bolt [a] on both sides, and take off the rear fender [b]. Rear flap removal • remove the screws [a]...

  • Page 444

    15-10 frame footpegs and brackets footpeg installation • apply a non-permanent locking agent to the footpeg bracket bolts [a]. • install the footpeg bracket [b], and tighten the bolts. Torque - footpeg bracket bolt (upper): 54 n·m (5.5 kgf·m, 40 ft·lb) • apply grease to the pivot pin [c]. • install ...

  • Page 445: Electrical System

    Electrical system 16-1 16 electrical system table of contents exploded view........................................................................................................................ 16-2 specifications .......................................................................................

  • Page 446

    16-2 electrical system exploded view kx250yb model.

  • Page 447

    Electrical system 16-3 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 flywheel nut cap 4.9 0.50 43 in·lb 2 magneto cover bolts 9.8 1.0 87 in·lb 3 timing inspection cap 3.9 0.40 35 in·lb 4 gear position switch screws 2.9 0.30 26 in·lb l 5 flywheel nut 78 8.0 58 6 crankshaft sensor bolts ...

  • Page 448

    16-4 electrical system exploded view kx250yc model.

  • Page 449

    Electrical system 16-5 exploded view torque no. Fastener n·m kgf·m ft·lb remarks 1 flywheel nut cap 4.9 0.50 43 in·lb 2 magneto cover bolts 9.8 1.0 87 in·lb 3 timing inspection cap 3.9 0.40 35 in·lb 4 gear position switch screws 2.9 0.30 26 in·lb l 5 flywheel nut 78 8.0 58 6 crankshaft sensor bolts ...

  • Page 450

    16-6 electrical system specifications item standard magneto magneto output voltage 6 v or more at 2 000 r/min (rpm) stator coil resistance 0.4 ∼ 1.1 Ω (at 20°c (68°f)) ignition system ignition timing 4° btdc @2 000 r/min (rpm) ignition coil: 3 needle arcing distance 7 mm (0.26 in.) or more primary w...

  • Page 451

    Electrical system 16-7 special tools and sealant rotor puller, m16/m18/m20/m22 × 1.5: 57001-1216 timing light: 57001-1241 hand tester: 57001-1394 peak voltage adapter: 57001-1415 filler cap driver: 57001-1454 needle adapter set: 57001-1457 flywheel puller, m28 × 1.0: 57001-1471 grip: 57001-1591 roto...

  • Page 452

    16-8 electrical system wiring diagram kx250yb model.

  • Page 453

    Electrical system 16-9 wiring diagram.

  • Page 454

    16-10 electrical system wiring diagram kx250yc model.

  • Page 455

    Electrical system 16-11 wiring diagram.

  • Page 456

    16-12 electrical system precautions there are numbers of important precautions that are musts when servicing electrical systems. Learn and ob- serve all the rules below. ○ the electrical parts should never be struck sharply, as with a hammer, or allowed to fall on a hard surface. Such a shock to the...

  • Page 457

    Electrical system 16-13 electrical wiring wiring inspection • visually inspect the wiring for signs of burning, fraying, etc. If any wiring is poor, replace the damaged wiring. • pull each connector [a] apart and inspect it for corrosion, dirt, and damage. If the connector is corroded or dirty, clea...

  • Page 458

    16-14 electrical system flywheel magneto magneto cover removal • drain the engine oil (see engine oil change in the peri- odic maintenance chapter). • remove: left radiator shroud (see radiator shroud removal in the frame chapter) shift pedal (see external shift mechanism removal in the crankshaft/t...

  • Page 459

    Electrical system 16-15 flywheel magneto • hold the flywheel steady with the rotor holder [a], and remove the flywheel nut [b]. Special tools - grip [c]: 57001-1591 rotor holder: 57001-1730 • remove the flywheel holder. • screw the flywheel puller [a] into the flywheel. • screw the rotor puller [b] ...

  • Page 460

    16-16 electrical system flywheel magneto • hold the flywheel steady with the rotor holder, and tighten the flywheel nut. Special tools - grip: 57001-1591 rotor holder: 57001-1730 torque - flywheel nut: 78 n·m (8.0 kgf·m, 58 ft·lb) • install the magneto cover (see magneto cover installa- tion). Stato...

  • Page 461

    Electrical system 16-17 flywheel magneto flywheel inspection there are three types of magneto problems: short, open (lead burned out), or loss in flywheel. A short or open in one of the coil leads will result in either a low output, or no output at all. A loss in flywheel, which may be caused by dro...

  • Page 462

    16-18 electrical system charging system regulator/rectifier removal/installation • remove: right radiator shroud (see radiator shroud removal in the frame chapter) regulator/rectifier bracket bolts [a] • disconnect the regulator/rectifier connector [a]. • remove the regulator/rectifier nuts [b], and...

  • Page 463

    Electrical system 16-19 charging system capacitor removal • disconnect the connector [a], and pull the capacitor [b] upward. Capacitor inspection • remove: capacitor (see capacitor removal) • set the hand tester to the × 1 kΩ range, connect the tester to the leads of the capacitor, and check the int...

  • Page 464

    16-20 electrical system ignition timing ignition timing inspection • remove the timing inspection cap[a]. Special tool - filler cap driver: 57001-1454 • attach the timing light [a] to the ignition coil lead in the manner prescribed by the manufacturer. Special tool - timing light: 57001-1241 • start...

  • Page 465

    Electrical system 16-21 ignition system safety instructions warning the ignition system produces extremely high volt- age. Do not touch the spark plug, ignition coil or ig- nition coil lead while the engine is running, or you could receive a severe electrical shock. Ignition coil removal • remove th...

  • Page 466

    16-22 electrical system ignition system • connect the primary lead connector. • install: ignition coil [a] with bracket ignition coil ground lead [b] ignition coil bracket bolt [c] ○ turn the clamp side of the ignition coil ground lead termi- nal outside. Ignition coil inspection measuring arcing di...

  • Page 467

    Electrical system 16-23 ignition system measuring coil resistance if the arcing tester is not available, the coil can be checked for a broken or badly shorted winding with an ohmmeter. However, an ohmmeter cannot detect layer shorts and shorts resulting from insulation breakdown under high voltage. ...

  • Page 468

    16-24 electrical system ignition system ignition coil primary peak voltage check • disconnect the spark plug cap from the spark plug, but do not remove the spark plug. • connect the good spark plug [a] to the spark plug cap, then touch the frame with it. Note ○ measure the voltage with each lead con...

  • Page 469

    Electrical system 16-25 ignition system.

  • Page 470

    16-26 electrical system ignition system crankshaft sensor peak voltage check • to check the peak voltage, do the following procedures. ○ disconnect the magneto lead connector (see magneto cover removal). Note ○ measure the voltage with each lead connected cor- rectly. The correct value may not be ob...

  • Page 471

    Electrical system 16-27 ignition system crankshaft sensor inspection • disconnect the magneto lead connector (see magneto cover removal). • set the hand tester [a] to the × 100 Ω range and connect it to the green/white [b] and white/yellow [c] leads in the connector. Special tool - hand tester: 5700...

  • Page 472

    16-28 electrical system switches engine stop switch inspection • using the hand tester, check to see that only the con- nections shown in the table have continuity (about zero ohms). Special tool - hand tester: 57001-1394 if the switch has an open or short, repair it or replace it with a new one. En...

  • Page 473: Appendix

    Appendix 17-1 17 appendix table of contents cable, wire, and hose routing .............................................................................................. 17-2 troubleshooting guide ...........................................................................................................

  • Page 474

    17-2 appendix cable, wire, and hose routing 1. Throttle cable (accelerator) 2. Throttle cable (decelerator) 3. Bands (hold the engine stop switch lead.) 4. Engine stop switch lead 5. Clutch cable 6. Run the engine stop switch lead and clutch cable into the guide. 7. Run the throttle cables into the ...

  • Page 475

    Appendix 17-3 cable, wire, and hose routing kx250yb model 1. Joint hose 2. Run the throttle cables between the frame pipe and right radiator. 3. Throttle cables 4. Clutch cable 5. Clamp (wind the clamp on the cable.) 6. Clamp 7. Run the clutch cable outside of the main harness. 8. Run the throttle c...

  • Page 476

    17-4 appendix cable, wire, and hose routing kx250yc model 1. Throttle cables 2. Run the throttle cables over the joint hose. 3. Run the throttle cables through the side of the fuel tank. 4. Run the throttle cables through the side of the frame. 5. Joint hose 6. Run the throttle cables between the fr...

  • Page 477

    Appendix 17-5 cable, wire, and hose routing this page intentionally left blank..

  • Page 478

    17-6 appendix cable, wire, and hose routing kx250yb model.

  • Page 479

    Appendix 17-7 cable, wire, and hose routing 1. Run the joint hose over the main harness. 2. Run the ignition coil connector under the main harness. 3. Clamp the main harness and the end of the ignition coil connector. 4. Vehicle-down sensor connector 5. Run the vehicle-down sensor lead outside of th...

  • Page 480

    17-8 appendix cable, wire, and hose routing kx250yc model.

  • Page 481

    Appendix 17-9 cable, wire, and hose routing 1. Run the joint hose over the main harness. 2. Run the ignition coil connector under the main harness. 3. Clamp (hold the main harness.) 4. Clamp the main harness and the end of the ignition coil connector. 5. Vehicle-down sensor connector 6. Run the vehi...

  • Page 482

    17-10 appendix cable, wire, and hose routing kx250yb model 1. Run the fuel pump lead over the fuel hose. 2. Fuel hose 3. Yellow paint.

  • Page 483

    Appendix 17-11 cable, wire, and hose routing kx250yc model 1. Run the fuel pump lead over the fuel hose. 2. Fuel hose 3. Yellow paint (red paint for brazil model only.).

  • Page 484

    17-12 appendix cable, wire, and hose routing kx250yc model 1. Fuel hose 2. Yellow paint (red paint for brazil model only.).

  • Page 485

    Appendix 17-13 cable, wire, and hose routing kx250yb model 1. Sub-harness connector (black) 2. Sub-harness connector (green) 3. Sub-harness bracket 4. Insert the sub-harness bracket into the frame bracket. 5. Regulator/rectifier connector 6. Throttle cables 7. Run the regulator/rectifier lead outsid...

  • Page 486

    17-14 appendix cable, wire, and hose routing kx250yc model 1. Fi warning indicator light harness connector 2. Kawasaki diagnostic system connector 3. Run the regulator/rectifier lead outside of the throttle cables. 4. Throttle cables 5. Regulator/rectifier connector 6. Run the regulator/rectifier le...

  • Page 487

    Appendix 17-15 cable, wire, and hose routing kx250yb model 1. Front 2. Spark plug cap 3. Clamp (wind the clamp on the harnesses at the gray taped position as shown in the figure.) 4. Clamp (wind the clamp on the harnesses as shown in the figure.) 5. Run the gear position switch lead inside of the ga...

  • Page 488

    17-16 appendix cable, wire, and hose routing kx250yc model 1. Front 2. Spark plug cap 3. Clamp (wind the clamp on the harnesses at the gray taped position as shown in the figure.) 4. Clamp (wind the clamp on the harnesses as shown in the figure.) 5. Do not pinch the gear position switch lead. 6. Run...

  • Page 489

    Appendix 17-17 cable, wire, and hose routing kx250yb model 1. To main harness 2. Clamp the sub-harness at the blue tape portion. 3. To intake air temperature sensor 4. Clamp the water temperature sensor lead and throttle sensor lead at the blue tape portion. 5. To water temperature sensor 6. Throttl...

  • Page 490

    17-18 appendix cable, wire, and hose routing kx250yc model 1. Clamp the sub-harness at the blue tape portion. 2. To intake air temperature sensor 3. Clamp the water temperature sensor lead and throttle sensor lead at the blue tape portion. 4. Throttle sensor connector 5. Injector connector 6. Intake...

  • Page 491

    Appendix 17-19 cable, wire, and hose routing 1. Intake air temperature sensor lead 2. Run the intake air temperature sensor lead through the hole of the guide as shown. 3. Bracket 4. Do not show up the intake air temperature sensor lead above the bracket as shown. 5. Do not bend the intake air tempe...

  • Page 492

    17-20 appendix cable, wire, and hose routing 1. Viewed rear 2. Viewed a 3. Viewed b 4. Joint hose (turn the blue paint to upside.) 5. Clamps 6. Clamps (turn the screw head to outside.) 7. Right radiator 8. Water pipe 9. Joint pipe 10. Left radiator 11. Radiator overflow hose 12. Capacitor (position ...

  • Page 493

    Appendix 17-21 cable, wire, and hose routing 1. Clamp (turn the claw to the exhaust pipe side.) 2. Clamp the breather hose from outside. 3. Breather hose 4. Install the mesh protector side of the breather hose to the engine. 5. Viewed a 6. Viewed front 7. Clamp (turn the screw head to outside.) 8. T...

  • Page 494

    17-22 appendix cable, wire, and hose routing 1. Touch the front brake hose fitting to the stopper. 2. Brake hose 3. Clamps 4. Viewed a 5. Clamp.

  • Page 495

    Appendix 17-23 cable, wire, and hose routing 1. Brake hose 2. Clamps 3. Touch the rear brake hose fitting to the stopper. 4. Cotter pin.

  • Page 496

    17-24 appendix troubleshooting guide note ○ refer to the fuel system (dfi) chapter for most of dfi trouble shooting guide. ○ this is not an exhaustive list, giving every possible cause for each problem listed. It is meant simply as a rough guide to assist the troubleshooting for some of the more com...

  • Page 497

    Appendix 17-25 troubleshooting guide poor running or no power at high speed: firing incorrect: spark plug dirty, broken, or gap malad- justed spark plug cap or high tension wiring trou- ble spark plug cap shorted or not in good con- tact spark plug incorrect heat value ecu trouble crankshaft sensor ...

  • Page 498

    17-26 appendix troubleshooting guide shift return spring weak or broken shift shaft lever broken pawl guide plate broken shift pawl broken shift pawl spring tension lose gear seized gear positioning lever operation trouble shift drum broken jumps out of gear: shift fork ear worn, bent gear groove wo...

  • Page 499

    Appendix 17-27 troubleshooting guide handling and/or stability unsatisfactory: handlebar hard to turn: cable, hose, wire routing incorrect steering stem nut too tight steering stem bearing damaged steering stem bearing lubrication inade- quate steering stem bent tire air pressure too low handlebar s...

  • Page 500

    Model application year model beginning frame no. 2011 kx250yb jkakxmyc □ ba000001 jkakx250yya000001 2012 kx250yc jkakxmyc □ ca013001 jkakx250yya013001 □ :this digit in the frame number changes from one machine to another. Part no.99924-1437-02 printed in japan.