2002 YAMAHA YZ125LC clutch

4-31
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC498100
PRIMARY DRIVEN GEAR
Extent of removal Order Part name Q’ty Remarks
PRIMARY DRIVEN GEAR
REMOVAL
1 Nut (clutch boss) 1
Use special tool.
2 Lock washer 1
Refer to “REMOVAL POINTS”.
3 Clutch boss 1
4
Plain washer [φ34 mm (1.34 in)] 1
5 Primary driven gear 1
6 Bearing 1
7
Plain washer [φ34 mm (1.34 in)]1
8 Push lever 1
Extent of removal:1Primary driven gear removal2Push lever removal
1
2





80 Nm (8.0 m•kg, 58 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
5NY-9-30-4B 1/7/04 4:49 PM Page 28

4-32
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC493000
REMOVAL POINTS
EC483211
Clutch boss
1. Remove:
9Nut 1
9Lock washer 2
9Clutch boss 3
NOTE:
Straighten the lock washer tab and use the
clutch holding tool 4, 5to hold the clutch boss.
å
For USA and CDN
∫
Except for USA and CDN
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
Clutch housing 1
Cracks/Wear/Damage  Replace.
9Clutch boss 2
Scoring/Wear/Damage Replace.
EC484201
Primary driven gear
1. Check:
9Circumferential play
Free play exists Replace.
9Gear teeth a
Wear/ Damage Replace.
EC484400
Clutch spring
1. Measure:
9Clutch spring free length a
Out of specification Replace springs as
a set.
Clutch holding tool:
YM-91042................................
4 4
90890-04086............................5 5
Clutch spring free length:
Standard
41.2 mm 39.2 mm
(1.622 in) (1.543 in)
å
∫å
5NY-9-30-4B 5/23/01 8:48 PM Page 30

4-33
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC484500
Friction plate
1. Measure:
9Friction plate thickness
Out of specification Replace friction
plate as a set.
Measure at all four points.
EC484600
Clutch plate
1. Measure:
9Clutch plate warpage
Out of specification Replace clutch plate
as a set.
Use a surface plate 1and thickness
gauge 2.
EC494100
Push lever and push rod
1. Inspect:
9Push lever 1
9Push rod 2
Wear/Damage Replace.
EC494200
Clutch cover
1. Inspect:
9Push rod bearing portion a
Wear/Damage Replace.
Friction plate thickness:
Standard
2.9~3.1 mm 2.8 mm
(0.114~0.122 in) (0.110 in)
Warp limit:
0.2 mm (0.008 in)
5NY-9-30-4B 5/23/01 8:48 PM Page 32

4-34
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC495000
ASSEMBLY AND INSTALLATION
EC495240
Clutch
1. Install:
9Plain washer [φ34 mm (1.34 in)] 1
9Spacer 2
9Bearing 3
9Primary driven gear 4
NOTE:
Apply the transmission oil on the spacer, bearing
and primary driven gear inner circumference.
2. Install:
9Plain washer [φ34 mm (1.34 in)] 1
9Clutch boss 2
3. Install:
9Lock washer 1
9Nut (clutch boss) 2
NOTE:
Use the clutch holding tool 3, 4to hold the
clutch boss.
å
For USA and CDN
∫
Except for USA and CDN
4. Bend the lock washer 1tab.
80 Nm (8.0 m•kg, 58 ft•lb)
Clutch holding tool:
YM-91042...............................3 3
90890-04086...........................4 4
å
∫
5NY-9-30-4B 1/7/04 4:49 PM Page 34

4-35
ENGCLUTCH AND PRIMARY DRIVEN GEAR
5. Install:
9Friction plate 1 1
9Clutch plate 2
9Friction plate 2 3
NOTE:
9Install the clutch plates and friction plates alter-
nately on the clutch boss, starting with a friction
plate and ending with a friction plate.
9Use the friction plates 1 for the first and final
while paying attention to the difference in sur-
face pattern.
9Apply the transmission oil on the friction plates
and clutch plates.
10 Nm (1.0 m•kg, 7.2 ft•lb)
8. Install:
9Clutch spring 1
9Screw (clutch spring) 2
NOTE:
Tighten the screws in stage, using a crisscross
pattern.
6. Install:
9Push rod 1
9Plain washer 2
9Bearing 3
To pressure plate 4.
NOTE:
Apply the lithium soap base grease on the bear-
ing, plain washer and push rod.
7. Install:
9Pressure plate 1
5NY-9-30-4B 5/23/01 8:48 PM Page 36

4-36
ENGCLUTCH AND PRIMARY DRIVEN GEAR
EC495121
Push lever
1. Install:
9Torsion spring 1
9Push lever 2
To push lever axle 3.
NOTE:
9Install the push lever with its 5mark a
downward.
9Temporarily install the torsion spring and push
lever at this point.
2. Check:
9Push lever position
NOTE:
When pushing the push lever forward, the front
line bshould be within the range a. If not, rein-
stall the push lever.
3. Adjust:
9Push lever position 10. Install:
9Clutch cover 1
9Bolt (clutch cover) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
10 Nm (1.0 m•kg, 7.2 ft•lb)
Adjustment steps:
9Remove the push lever 1from the push
lever axle 2.
9Re-install the push lever so that the projec-
tion is positioned between alignment marks
when pushing the push lever forward.
9. Install:
9Gasket (clutch cover) 1
NOTE:
Position the rack aon the push rod backward.
5NY-9-30-4B 5/23/01 8:48 PM Page 38

4-37
ENGCLUTCH AND PRIMARY DRIVEN GEAR
4. Install:
9Plain washer 1
9Circlip 2
5NY-9-30-4B 5/23/01 8:48 PM Page 40

4-38
ENG
KICK AXLE, SHIFT SHAFT AND PRIMARY DRIVE
GEAR
Extent of removal Order Part name Q’ty Remarks
RPIMARY DRIVE GEAR REMOVAL
Preparation for Drain the transmission oil.Refer to “TRANSMISSION OIL REPLACE-
removalMENT“ section in the CHAPTER 3.
Clutch cable Disconnect at engine side.
Bolt (brake pedal) Shift the brake pedal downward.
Radiator hose 4 Disconnect at water pump side.
Bolt (push rod)
Refer to “CYLINDER HEAD, CYLINDER
AND PISTON” section.
1 Kick starter 1
2 Crankcase cover (right) 1
3 Bolt (Primary drive gear) 1 Only loosening
Refer to “REMOVAL POINTS”.
4 Primary driven gear 1 Refer to “CLUTCH AND PRIMARY
DRIVEN GEAR”section.
5 Primary drive gear 1
EC4C0000
KICK AXLE, SHIFT SHAFT AND PRIMARY DRIVE GEAREC4C8000PRIMARY DRIVE GEAR
1
Extent of removal:1Primary drive gear removal
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
55 Nm (5.5 m•kg, 40 ft•lb)
5NY-9-30-4C 5/23/01 8:56 PM Page 2