2002 YAMAHA YZ125LC wheel

3-26
FRONT FORK INSPECTION
INSP
ADJ
3. Adjust:
9Drive chain slack
EC36C000
FRONT FORK INSPECTION
1. Inspect:
9Front fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage Repair or
replace.
Drive chain slack adjustment steps:
9Loosen the axle nut 1and locknuts 2.
9Adjust chain slack by turning the
adjusters 3.
To tighten Turn adjuster 3 3
counter-
clockwise.
To loosen Turn adjuster 3 3
clockwise
and push wheel forward.
9Turn each adjuster exactly the same amount
to maintain correct axle alignment. (There are
marks aon each side of chain puller align-
ment.)
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
cC
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
9Tighten the axle nut while pushing down the
drive chain.
9Tighten the locknuts.
Axle nut:
125 Nm (12.5 m•kg, 90 ft•lb)
5NY-9-30-3B 5/23/01 8:33 PM Page 16

3-27
FRONT FORK OIL SEAL AND DUST SEAL CLEANING/
FRONT FORK INTERNAL PRESSURE RELIEVING/
FRONT FORK REBOUND DAMPING FORCE ADJUSTMENTINSP
ADJ
EC36D001
FRONT FORK OIL SEAL AND DUST SEAL
CLEANING
1. Remove:
9Protector
9Dust seal 1
NOTE:
Use a thin screw driver, and be careful not to
damage the inner fork tube and dust seal.
2. Clean:
9Dust seal a
9Oil seal b
NOTE:
9Clean the dust seal and oil seal after every
run.
9Apply the lithium soap base grease on the in-
ner tube.
EC36H002
FRONT FORK REBOUND DAMPING FORCE
ADJUSTMENT
1. Adjust:
9Rebound damping force
By turning the adjuster 1.
Stiffer a a
Increase the rebound damping
force. (Turn the adjuster 1 1
in.)
Softer b b
Decrease the rebound
damping force. (Turn the
adjuster 1 1
out.)
EC36f000
FRONT FORK INTERNAL PRESSURE
RELIEVING
NOTE:
If the front fork initial movement feels stiff during
a run, relieve the front fork internal pressure.
1. Elevate the front wheel by placing a suitable
stand under the engine.
2. Remove the air bleed screw 1and release
the internal pressure from the front fork.
3. Install:
9Air bleed screw
1 Nm (0.1 m•kg, 0.7 ft•lb)
5NY-9-30-3B 5/23/01 8:33 PM Page 18

3-30
REAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENTINSP
ADJ
EC36M013
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Remove:
9Rear frame
3. Loosen:
9Locknut 1
4. Adjust:
9Spring preload
By turning the adjuster 2.
NOTE:
9Be sure to remove all dirt and mud from
around the locknut and adjuster before
adjustment.
9The length of the spring (installed) changes 1.5
mm (0.06 in) per turn of the adjuster.
cC
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:
9Locknut
6. Install:
9Rear frame
Stiffer Increase the spring preload.
(Turn the adjuster 2 2
in.)
Softer Decrease the spring pre-
load. (Turn the adjuster 2 2
out.)
Extent of adjustment
240.5~258.5 mm
(9.47~10.18 in)
*255.5~273.5 mm
(10.06~10.77 in)
Spring length (installed) a a
:
Standard length
248 mm (9.76 in)
*262 mm (10.31 in)
*For EUROPE
29 Nm (2.9 m•kg, 21 ft•lb)
5NY-9-30-3B 5/23/01 8:34 PM Page 24

3-34
TIRE PRESSURE CHECK/SPOKES INSPECTION AND
TIGHTENING/WHEEL INSPECTIONINSP
ADJ
EC36Q001
TIRE PRESSURE CHECK
1. Measure:
9Tire pressure
Out of specification Adjust.
NOTE:
9Check the tire while it is cold.
9Loose bead stoppers allow the tire to slip off its
position on the rim when the tire pressure is
low.
9A tilted tire valve stem indicates that the tire
slips off its position on the rim.
9If the tire valve stem is found tilted, the tire is
considered to be slipping off its position.
Correct the tire position.
EC36S002
SPOKES INSPECTION AND TIGHTENING
1. Inspect:
9Spokes 1
Bend/Damage Replace.
Loose spoke Retighten.
2. Tighten:
9Spokes
NOTE:
Be sure to retighten these spokes before and af-
ter break-in. After a practice or a race check
spokes for looseness.
EC36T000
WHEEL INSPECTION
1. Inspect:
9Wheel runout
Elevate the wheel and turn it.
Abnormal runout Replace.
Standard tire pressure:
100 kPa (1.0 kgf/cm
2, 15 psi)
3 Nm (0.3 m•kg, 2.2 ft•lb)
5NY-9-30-3B 5/23/01 8:34 PM Page 32

3-35
STEERING HEAD INSPECTION AND ADJUSTMENT
INSP
ADJ
2. Inspect:
9Bearing free play
Exist play Replace.
EC36U013
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suitable
stand under the engine.
2. Check:
9Steering shaft
Grasp the bottom of the forks and gently
rock the fork assembly back and forth.
Free play Adjust steering head.
3. Check:
9Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action Adjust steering ring
nut.
4. Adjust:
9Steering ring nut
Steering ring nut adjustment steps:
9Remove the number plate.
9Remove the handlebar and handle crown.
9Loosen the ring nut 1using the ring nut
wrench 2.
9Tighten the ring nut 3using ring nut
wrench 4.
NOTE:
Set the torque wrench to the ring nut wrench
so that they form a right angle.
Ring nut wrench:
YU-33975/90890-01403
5NY-9-30-3B 5/23/01 8:34 PM Page 34

4-54
ENGCDI MAGNETO
EC4L3000
REMOVAL POINTS
EC4L3102
Rotor
1. Remove:
9Nut (rotor) 1
9Plain washer 2
Use the rotor holding tool 3.
2. Remove:
9Rotor 1
Use the flywheel puller 2.
NOTE:
When installing the flywheel puller, turn it coun-
terclockwise.
EC4L4000
INSPECTION
EC4L4101
CDI magneto
1. Inspect:
9Rotor inner surface a
9Stator outer surface b
Damage Inspect the crankshaft runout
and crankshaft bearing.
If necessary, replace CDI magneto and/or
stator.
EC4L4200
Woodruff key
1. Inspect:
9Woodruff key 1
Damage Replace.
EC4L5000
ASSEMBLY AND INSTALLATION
EC4L5172
CDI magneto
1. Install:
9Stator 1
9Screw (stator) 2
NOTE:
Temporarily tighten the screw (stator) at this
point.
Rotor holding tool:
YU-1235/90890-01235
Flywheel puller:
YM-1189/90890-01189
5NY-9-30-4C 5/23/01 8:56 PM Page 34

4-72
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
2. Install:
93rd wheel gear (29T) 1
94th wheel gear (24T) 2
92nd wheel gear (31T) 3
95th wheel gear (25T) 4
91st wheel gear (27T) 5
To drive axle 6.
NOTE:
9Apply the molybdenum disulfide oil on the 1st,
2nd and 3rd wheel gears inner circumference
and on the end surface.
9Apply the molybdenum disulfide oil on the 4th
and 5th wheel gears inner circumference.
3. Install:
9Plain washer 1
9Circlip 2
NOTE:
9Be sure the circlip sharp-edged corner ais po-
sitioned opposite side to the plain washer and
gear b.
9Be sure the circlip end cis positioned at axle
spline groove d.
4. Install:
9Spacer 1
NOTE:
9Apply the lithium soap base grease on the oil
seal lip.
9When installing the spacer into the crankcase,
pay careful attention to the crankcase oil seal
lip.
5NY-9-30-4D 5/24/01 8:33 PM Page 32

4-73
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H5312
Shift cam and shift fork
1. Install:
9Shift fork 1 (L) 1
9Shift fork 2 (C) 2
9Shift fork 3 (R) 3
NOTE:
9Mesh the shift fork #1 (L) with the 4th wheel
gear 4and #3 (R) with the 5th wheel gear 6
on the drive axle.
9Mesh the shift fork #2 (C) with the 3rd pinion
gear 5on the main axle.
2. Install:
9Shift cam 1
NOTE:
9Apply the transmission oil on the shift cam.
9Install the shift cam while holding up the 4th
wheel gear 2and keeping the shift fork #1 3
moved in the direction of the arrow.
3. Install:
9Guide bar (short) 1
9Guide bar (long) 2
NOTE:
9Apply the transmission oil on the guide bars.
9Be sure the long bar is inserted into the shift
forks #1 and #3 and the short one into #2.
5. Install:
9Main axle 1
9Drive axle 2
NOTE:
Apply the transmission oil on the crankcase
bearings.
5NY-9-30-4D 5/24/01 8:34 PM Page 34