2001 YAMAHA YZ426F wheel

3 - 33
INSP
ADJ
FRONT FORK INSPECTION
3. Adjust:
lDrive chain slack
Drive chain slack adjustment steps:
lLoosen the axle nut 1 and locknuts 2.
lAdjust chain slack by turning the adjusters
3.
To tighten ® Turn adjuster 3 counter-
clockwise.
To loosen ® Turn adjuster 3 clockwise
and push wheel forward.
lTurn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of chain
puller alignment.)
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
lTighten the axle nut while pushing down
the drive chain.
T R..
Axle nut:
125 Nm (12.5 m • kg, 90 ft • lb)
lTighten the locknuts.
EC36C000
FRONT FORK INSPECTION
1. Inspect:
lFront fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage ® Repair
or replace.

3 - 37
INSP
ADJREAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENT
EC36M013
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Remove:
lRear frame
3. Loosen:
lLocknut 1
4. Adjust:
lSpring preload
By turning the adjuster 2.
* For EUROPE
NOTE:
lBe sure to remove all dirt and mud from
around the locknut and adjuster before
adjustment.
lThe length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:
lLocknut
6. Install:
lRear frame Stiffer ®Increase the spring preload.
(Turn the adjuster 2 in.)
Softer ®Decrease the spring preload.
(Turn the adjuster 2 out.)
Spring length (installed) a:
Standard lengthExtent of adjustment
248 mm (9.76 in)
*262 mm (10.31 in)247 ~ 265 mm
(9.72 ~ 10.43 in)
*257 ~ 275 mm
(10.12 ~ 10.83 in)
T R..29 Nm (2.9 m · kg, 21 ft · lb)

3 - 41
INSP
ADJTIRE PRESSURE CHECK/SPOKES INSPECTION AND
TIGHTENING/WHEEL INSPECTION
EC36Q000
TIRE PRESSURE CHECK
1. Measure:
lTire pressure
Out of specification ® Adjust.
NOTE:
lCheck the tire while it is cold.
lLoose bead stoppers allow the tire to slip off
its position on the rim when the tire pressure
is low.
lA tilted tire valve stem indicates that the tire
slips off its position on the rim.
lIf the tire valve stem is found tilted, the tire is
considered to be slipping off its position. Cor-
rect the tire position.
Standard tire pressure:
100 kPa (1.0 kg/cm2, 15 psi)
EC36S002
SPOKES INSPECTION AND TIGHTENING
1. Inspect:
lSpokes 1
Bend/damage ® Replace.
Loose spoke ® Retighten.
2. Tighten:
lSpokes
NOTE:
Be sure to retighten these spokes before and
after break-in. After a practice or a race check
spokes for looseness.
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)
EC36T000
WHEEL INSPECTION
1. Inspect:
lWheel runout
Elevate the wheel and turn it.
Abnormal runout ® Replace.

3 - 42
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
2. Inspect:
lBearing free play
Exist play ® Replace.
EC36U013
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suit-
able stand under the engine.
2. Check:
lSteering shaft
Grasp the bottom of the forks and gen-
tly rock the fork assembly back and
forth.
Free play ® Adjust steering head.
3. Check:
lSteering smooth action
Turn the handlebar lock to lock.
Unsmooth action ® Adjust steering ring
nut.
4. Adjust:
lSteering ring nut
Steering ring nut adjustment steps:
lRemove the number plate.
lRemove the handlebar and handle crown.
lLoosen the ring nut 1 using the ring nut
wrench 2.
Ring nut wrench:
YU-33975/90890-01403

4 - 66
ENGKICK AXLE AND SHIFT SHAFT
KICK AXLE AND SHIFT SHAFT
KICK AXLE AND SHIFT SHAFT
Extent of removal:1 Kick axle removal2 Kick axle disassembly
3 Shift shaft removal4 Segment removal
Extent of removal Order Part name Q’ty Remarks
KICK AXLE AND SHIFT SHAFT
REMOVAL
Preparation for removal Shift pedal Refer to “CDI MAGNETO” section.
Oil pump Refer to “OIL PUMP” section.
1 Kick idle gear 1
2 Kick axle assembly 1 Refer to “REMOVAL POINTS”.
3 Spring guide 1
4 Torsion spring 1
5 Ratchet wheel 1
6 Kick gear 1
7 Kick axle 1
8 Plain washer 1
9 Shift shaft 1
10Collar
1
3
2
1
4
1

4 - 68
ENGKICK AXLE AND SHIFT SHAFT
REMOVAL POINTS
EC4B3101
Kick axle assembly
1. Remove:
lKick axle assembly 1
NOTE:
Unhook the torsion spring 2 from the hole a
in the crankcase.
EC4C3101
Shift guide and shift lever assembly
1. Remove:
lBolt (shift guide)
lShift guide 1
lShift lever assembly 2
NOTE:
The shift lever assembly is disassembled at
the same time as the shift guide.
EC4N3100
Segment
1. Remove:
lBolt (segment) 1
lSegment 2
NOTE:
Turn the segment counterclockwise until it
stops and loosen the bolt.
INSPECTION
EC4C4200
Kick axle and ratchet wheel
1. Check:
lRatchet wheel 1 smooth movement
Unsmooth movement ® Replace.
lKick axle 2
Wear/damage ® Replace.
lSpring 3
Broken ® Replace.
EC4C4300
Kick gear, kick idle gear and ratchet wheel
1. Inspect:
lKick gear 1
lKick idle gear 2
lRatchet wheel 3
lGear teeth a
lRatchet teeth b
Wear/damage ® Replace.

4 - 71
ENGKICK AXLE AND SHIFT SHAFT
4. Install:
lBolt (shift guide) 1
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
EC4C5301
Shift shaft
1. Install:
lRoller 1
lCollar 2
lTorsion spring 3
lShift shaft 4
NOTE:
Apply the engine oil on the roller and shift
shaft.
Kick axle assembly
1. Install:
lKick gear 1
lPlain washer 2
lCirclip 3
lRatchet wheel 4
lSpring 5
lPlain washer 6
lCirclip 7
To kick axle 8.
NOTE:
lApply the molybdenum disulfide oil on the
kick gear inner circumference.
lAlign the punch mark a on the ratchet wheel
with the punch mark b on the kick axle.
New
New
2. Install:
lTorsion spring 1
To kick axle 2.
NOTE:
Make sure the stopper a of the torsion spring
fits into the hole b on the kick axle.

4 - 74
ENGCDI MAGNETO
EC4L3000
REMOVAL POINTS
EC4L3101
Rotor
1. Remove:
lNut (rotor) 1
lPlain washer
Use the rotor holding tool 2.
2. Remove:
lRotor 1
Use the flywheel puller 2.
NOTE:
When installing the flywheel puller, turn it
counterclockwise.
Rotor holding tool:
YU-1235/90890-01235
Flywheel puller:
YM-1189/90890-01189
EC4L4000
INSPECTION
EC4L4101
CDI magneto
1. Inspect:
lRotor inner surface a
lStator outer surface b
Damage ® Inspect the crankshaft
runout and crankshaft bearing.
If necessary, replace CDI magneto and/
or stator.
EC4L4200
Woodruff key
1. Inspect:
lWoodruff key 1
Damage ® Replace.