clutch YAMAHA WR 250F 2008 Owner's Manual

5-29
CLUTCH
CLUTCH
REMOVING THE CLUTCHOrder Part name Q'ty Remarks Drain the engine oil. Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
Brake pedal Refer to "ENGINE REMOVAL" section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Clutch spring 5
3 Pressure plate 1
4 Push rod 1 1
5 Circlip 1
6 Washer 1
7 Bearing 1
8Ball 1
9 Push rod 2 1
10 Friction plate 9
11 Clutch plate 8
12 Cushion spring 1
13 Seat plate 1

5-30
CLUTCH
14 Nut (clutch boss)1 Refer to removal section.
15 Lock washer 1 Refer to removal section.
16 Clutch boss 1 Refer to removal section.
17 Thrust washer 1
18 Primary driven gear 1
19 Push lever shaft 1
Order
Part name Q'tyRemarks

5-31
CLUTCH
REMOVING THE CLUTCH BOSS
1. Remove:•Nut "1"
• Lock washer "2"
• Clutch boss "3"
Straighten the lock washer tab and
use the clutch holding tool "4" to hold
the clutch boss.
A. For USA and CDN
B. Except for USA and CDN
CHECKING THE CLUTCH
HOUSING AND BOSS
1. Inspect: • Clutch housing "1"
Cracks/wear/damage →Replace.
• Clutch boss "2" Scoring/wear/damage →Replace.
CHECKING THE PRIMARY DRIVEN
GEAR
1. Check: • Circumferential play
Free play exists →Replace.
• Gear teeth "a" Wear/damage →Replace. CHECKING THE CLUTCH
SPRINGS
1. Measure:
• Clutch spring free length "a"
Out of specification →Replace
springs as a set.
CHECKING THE FRICTION
PLATES
1. Measure: • Friction plate thickness
Out of specification →Replace
friction plate as a set.
Measure at all four points.
CHECKING THE CLUTCH PLATES
1. Measure: • Clutch plate warpageOut of specification →Replace
clutch plate as a set.
Use a surface plate "1" and thick-
ness gauge "2". CHECKING THE PUSH LEVER
SHAFT
1. Inspect:
• Push lever shaft "1"
Wear/damage →Replace.
CHECKING THE PUSH ROD
1. Inspect: • Push rod 1 "1"
• Bearing "2"
• Washer "3"
• Push rod 2 "4"
•Ball "5"Wear/damage/bend →Replace.
INSTALLING THE PUSH LEVER
SHAFT
1. Install: • Push lever shaft "1"
• Bolt (push lever shaft) "2"
• Apply the lithium soap base grease
on the oil seal lip.
• Apply the engine oil on the push le- ver shaft.
• Fit the seat plate "3" in the groove "a" of the push lever shaft and tight-
en the bolt (seat plate).
INSTALLING THE CLUTCH
1. Install:• Primary driven gear "1"
• Thrust washer "2"
• Clutch boss "3"
Clutch holding tool:
YM-91042/90890-04086
Clutch spring free
length:
37.0 mm (1.46 in)
: 36.0 mm (1.42
in)
Friction plate thickness: 2.9–3.1 mm (0.114–
0.122 in)
: 2.7 mm (0.106
in)
Warp limit: 0.1 mm (0.004 in)
Bolt (push lever shaft): 10 Nm (1.0 m•kg, 7.2
ft•lb)

5-32
CLUTCH
Apply the engine oil on the primary
driven gear inner circumference.
2. Install:• Lock washer "1"
• Nut (clutch boss) "2"
Use the clutch holding tool "3" to hold
the clutch boss.
A. For USA and CDN
B. Except for USA and CDN
3. Bend the lock washer "1" tab.
4. Install: • Seat plate "1"
• Cushion spring "2"
• Install the seat plate with its cham-fered portion "a" facing the clutch
boss "3".
• Install the seat plate so that it is not caught on the step "b".
• Install the cushion spring with the paint "c" facing out.
5. Install:
• Friction plate 1 "1"
• Clutch plate 1 "2"
• Friction plate 2 "3"
• Clutch plate 2 "4"
• Install the clutch plates and friction plates alternately on the clutch
boss, starting with a friction plate
and ending with a friction plate.
• Use the friction plates 1 for the first and final while paying attention to
the difference in surface pattern.
• Apply the engine oil on the friction plates and clutch plates.
• Unlike the clutch pl ate 2, the clutch
plate 1 has no surface gloss. Use
the clutch plate 1 for the first while
paying attention to the difference in
surface gloss.
6. Install:
•Bearing "1"
• Washer "2"
• Circlip "3" To push rod 1 "4".
Apply the engine oil on the bearing
and washer.
7. Install:• Push rod 2 "1"
•Ball "2"
• Push rod 1 "3"
Apply the engine oil on the push rod
1, 2 and ball.
8. Install:• Pressure plate "1"
9. Install: • Clutch spring "1"
• Bolt (clutch spring) "2"
Tighten the bolts in stage, using a
crisscross pattern.
Nut (clutch boss): 60 Nm (6.0 m•kg, 43
ft•lb)
Clutch holding tool: YM-91042/90890-04086
Bolt (clutch spring):10 Nm (1.0 m•kg, 7.2
ft•lb)

5-33
CLUTCH
10. Install:• Dowel pin "1"
• Gasket (clutch cover) "2"
11. Install: • Clutch cover "1"
• Bolt (clutch cover)
Tighten the bolts in stage, using a
crisscross pattern.
Bolt (clutch cover): 10 Nm (1.0 m•kg, 7.2
ft•lb)

5-38
BALANCER
BALANCER
REMOVING THE BALANCEROrder Part name Q'ty Remarks Primary driven gear Refer to "CLUTCH" section.
Right crankcase cover Refer to "OIL FILTER ELEMENT AND WA-
TER PUMP" section.
Stator Refer to "AC MAGNETO AND STARTER
CLUTCH" section.
1 Nut (primary drive gear) 1 R efer to removal section.
2 Nut (balancer shaft driven gear) 1 Refer to removal section.
3 Lock washer 1
4 Primary drive gear 1
5 Balancer shaft drive gear 1
6 Lock washer 1
7 Balancer shaft driven gear 1
8 Balancer shaft 1 Refer to removal section.

5-40
OIL PUMP
OIL PUMP
REMOVING THE OIL PUMPOrder Part name Q'ty Remarks Primary driven gear Refer to "CLUTCH" section.
Right crankcase cover Refer to "OIL FILTER ELEMENT AND WA-
TER PUMP" section.
1 Circlip 1
2 Washer 1
3 Oil pump drive gear 1
4 Oil pump assembly 1
5 Outer rotor 2 1
6 Circlip 1
7 Inner rotor 2 1
8 Dowel pin 1
9 Oil pump cover 1
10 Outer rotor 1 1
11 Inner rotor 1 1
12 Dowel pin 1
13 Washer 1
14 Oil pump drive shaft 1
15 Rotor housing 1

5-46
KICK SHAFT AND SHIFT SHAFT
INSTALLING THE SHIFT GUIDE
AND SHIFT LEVER ASSEMBLY
1. Install:• Spring "1"
• Pawl pin "2"
•Pawl "3"To shift lever "4".
Apply the engine oil on the spring,
pawl pin and pawl.
2. Install:• Shift lever assembly "1"
To shift guide "2".
3. Install: • Shift lever assembly "1"
• Shift guide "2"
• The shift lever assembly is installed at the same time as the shift guide.
• Apply the engine oil on the bolt
(segment) shaft.
4. Install:• Bolt (shift guide) "1" INSTALLING TH
E SHIFT SHAFT
1. Install: • Roller "1"
• Collar "2"
• Torsion spring "3"
• Shift shaft "4"
Apply the engine oil on the roller and
shift shaft.
2. Install:• Shift pedalRefer to "AC MAGNETO AND
STARTER CLUTCH" section.
INSTALLING THE KICK SHAFT
ASSEMBLY
1. Install: • Kick gear "1"
• Washer "2"
• Circlip "3"
• Ratchet wheel "4"
• Spring "5"
• Washer "6"
• Circlip "7" To kick shaft "8".
• Apply the molybdenum disulfide oil on the inner circumferences of the
kick gear and ratchet wheel.
• Align the punch mark "a" on the ratchet wheel with the punch mark
"b" on the kick shaft.
2. Install:• Torsion spring "1"
To kick shaft "2".
Make sure the stopper "a" of the tor-
sion spring fits into the hole "b" on the
kick shaft.
3. Install:• Spring guide "1"
Slide the spring guide into the kick
shaft, make sure the groove "a" in the
spring guide fits on the stopper of the
torsion spring.
4. Install:• Kick shaft assembly "1"
• Washer "2"
• Apply the molybdenum disulfide
grease on the contacting surfaces
of the kick shaft stopper "a" and kick
shaft ratchet wheel guide "3".
• Apply the engine oil on the kick shaft.
• Slide the kick shaft assembly into the crankcase and make sure the
kick shaft stopper "a" fits into the
kick shaft ratchet wheel guide.
5. Hook:• Torsion spring "1"
Turn the torsion spring clockwise and
hook into the proper hole "a" in the
crankcase.Bolt (shift guide):
10 Nm (1.0 m•kg, 7.2
ft•lb)

5-48
AC MAGNETO AND STARTER CLUTCH
AC MAGNETO AND STARTER CLUTCH
REMOVING THE AC MAGNETO AND STARTER CLUTCHOrder Part name Q'ty Remarks Drain the engine oil. Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
Seat and fuel tank Refer to "REMOVING THE SEAT, FUEL
TANK AND SIDE COVERS" section in the
CHAPTER 3.
Disconnect the AC magneto lead.
1 Shift pedal 1
2 Cover (torque limiter) 1
3 Torque limiter 1 Do not disassemble.
4 Crankcase cover (left) 1
5 Gasket 1
6 Dowel pin 2
7* Nut (rotor) 1 Refer to NOTE.
8 Rotor 1 Refer to removal section.
9 Woodruff key 1
10 Starter clutch drive gear 1
11 Starter clutch assembly cover 1

5-49
AC MAGNETO AND STARTER CLUTCH
Tighten the rotor nut to 65 Nm (6.5 m•kg, 47 ft•lb), loosen and retighten the rotor nut to 65 Nm (6.5 m•kg, 47 ft•lb).
12 Starter clutch1 Refer to removal section.
13 Bearing 1
14 Washer 1
15 Idle gear plate 1
16 Idle gear 1
17 Holder 1
18 Pickup coil 1
19 Stator 1
Order
Part name Q'tyRemarks