2002 YAMAHA YZ250LC wheel

4-45
KICK AXLE, SHIFT SHAFT AND PRIMARY DRIVE GEARENG
EC4C5310
Shift shaft
1. Install:
9Roller 1
9Plain washer 2
9Shift shaft 3
NOTE:
Apply the transmission oil on the roller and shift
shaft.
2. Install:
9Torsion spring 1
To kick axle 2.
NOTE:
Make sure the stopper aof the torsion spring
fits into the hole bon the kick axle.
EC4C5601
Kick axle assembly
1. Install:
9Kick gear 1
9Plain washer 2
9Circlip 3
9Ratchet wheel 4
9Spring 5
9Plain washer 6
9Circlip 7
To kick axle 8.
NOTE:
9Apply the transmission oil on the kick gear
inner circumference.
9Align the punch mark aon the ratchet wheel
with the punck mark bon the kick axle.
4. Install:
9Bolt (shift guide) 1
10 Nm (1.0 m•kg, 7.2 ft•lb)
5NX-9-30-4B 6/7/01 1:56 PM Page 36

4-57
CDI MAGNETOENG
EC4L5000
ASSEMBLY AND INSTALLATION
EC4L5172
CDI magneto
1. Install:
9Stator 1
9Screw (stator) 2
NOTE:
Temporarily tighten the screw (stator) at this
point.
2. Remove:
9Rotor 1
Use the flywheel puller 2.
NOTE:
When installing the flywheel puller, turn it coun-
terclockwise.
EC4L3000
REMOVAL POINTS
EC4L3102
Rotor
1. Remove:
9Nut (rotor) 1
9Plain washer 2
Use the rotor holding tool 3.
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.
Rotor holding tool:
YU-1235/90890-01235
Flywheel puller:
YM-1189/90890-01189
5NX-9-30-4C 6/5/01 4:25 PM Page 16

4-75
TRANSMISSION, SHIFT CAM AND SHIFT FORKENG
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.
9Install the spacer with its chamfered side a
facing the crankcase.
3. Install:
9Plain washer 1
9Circlip 2
NOTE:
9Be sure the circlip sharp-edged corner ais
positioned opposite side to the plain washer
and gear b.
9Be sure the circlip end cis positioned at axle
spline groove d.
2. Install:
92nd wheel gear (25 T) 1
94th wheel gear (24 T) 2
93rd wheel gear (23 T) 3
95th wheel gear (20 T) 4
91st wheel gear (27 T) 5
9O-ring 6
To drive axle 7.
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.
9Apply the lithium soap base grease on the O-
ring.
5NX-9-30-4C 6/5/01 4:26 PM Page 52

4-76
TRANSMISSION, SHIFT CAM AND SHIFT FORKENG
5. Install:
9Shift fork 1 (L) 1
9Shift fork 2 (C10) 2
9Shift fork 3 (R) 3
9Shift cam 4
To main axle and drive axle.
NOTE:
9Apply the molybdenum disulfide oil on the shift
fork grooves.
9Mesh the shift fork #1 (L) with the 4th wheel
gear 5and #3 (R) with the 5th wheel gear 7
on the drive axle.
9Mesh the shift fork #2 (C10) with the 3rd pinion
gear 6on the main axle.
6. Install:
9Transmission assembly 1
To crankcase (left) 2.
NOTE:
Apply the transmission oil on the bearings and
guide bars.
7. Check:
9Shifter operation
9Transmission operation
Unsmooth operation
Repair.
5NX-9-30-4C 6/5/01 4:26 PM Page 54

5-1
CHASFRONT WHEEL AND REAR WHEEL
Extent of removal Order Part name Q’ty Remarks
FRONT WHEEL REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
1 Hose cover 1
2 Bolt (brake hose holder) 2 Only loosening.
3 Bolt (axle holder) 4 Only loosening.
4 Nut (front wheel axle) 1
5 Front wheel axle 1
6 Front wheel 1
7 Collar 2
8 Oil seal 2
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disk 1
EC500000
CHASSISEC590000
FRONT WHEEL AND REAR WHEELEC598000
FRONT WHEEL
2
13
3
Extent of removal:1Front wheel removal2Wheel bearing removal3Brake disc removal
w
Support the machine securely so there is no dan-
ger of it falling over.
5
23 Nm (2.3 m•kg, 17 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
105 Nm (10.5 m•kg, 75 ft•lb)
16 Nm (1.6 m•kg, 11 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)12 Nm (1.2 m•kg, 8.7 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
5NX-9-30-5A 6/7/01 2:00 PM Page 2

5-2
CHASFRONT WHEEL AND REAR WHEEL
EC598100
REAR WHEEL
Extent of removal:1Rear wheel removal2Wheel bearing removal3Brake disc removal
Extent of removal Order Part name Q’ty Remarks
REAR WHEEL REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Driven sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disk 1
2
13
3
w
Support the machine securely so there is no dan-
ger of it falling over.
125 Nm (12.5 m•kg, 90 ft•lb)
14 Nm (1.4 m•kg, 10 ft•lb)
42 Nm (4.2 m•kg, 30 ft•lb)
5NX-9-30-5A 6/7/01 2:00 PM Page 4

5-3
CHASFRONT WHEEL AND REAR WHEEL
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:
9Wheel 1
NOTE:
Push the wheel forward and remove the drive
chain 2.
EC513201
Wheel bearing (if necessary)
1. Remove:
9Bearing 1
NOTE:
Remove the bearing using a general bearing
puller 2.
EC594000
INSPECTION
EC514100
Wheel
1. Measure:
9Wheel runout
Out of limitRepair/Replace.
2. Inspect:
9Bearing
Rotate inner race with a finger.
Rough spot/SeizureReplace.
NOTE:
Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial
1 1
: 2.0mm (0.08 in)
Lateral 2 2
: 2.0mm (0.08 in)
5NX-9-30-5A 6/7/01 2:00 PM Page 6

5-4
CHASFRONT WHEEL AND REAR WHEEL
EC514200
Wheel axle
1. Measure:
9Wheel axle bends
Out of specificationReplace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
w
Do not attempt to straighten a bent axle.
EC594200
Brake disc
1. Measure:
9Brake disc deflection (only rear brake disc)
Use the dial gauge 1.
Out of specificationInspect wheel runout.
If wheel runout is in good condition, re-
place the brake disc.
2. Measure:
9Brake disc thickness a
Out of limitReplace.
Wheel axle bending limit:
0.5 mm (0.020 in)
Disc wear limit:
Standard
Front 3.0 mm (0.12 in) 2.5 mm (0.10 in)
Rear 4.0 mm (0.16 in) 3.5 mm (0.14 in)
Disc deflection limit:
Standard
Rear —
0.15 mm (0.006 in)
5NX-9-30-5A 6/7/01 2:00 PM Page 8