Yamaha 2011 YZ250F, Owner'S Service Manual

Page: 105 / 196

4-31
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 warpage
Out 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).
Clutch holding tool:
YM-91042/90890-04086
Clutch spring free
length:
35.7 mm (1.41 in)
<Limit>: 34.7 mm (1.37
in)
Friction plate thickness:
2.9–3.1 mm
(0.114–0.122 in)
<Limit>: 2.8 mm (0.110
in)
Warp limit:
0.1 mm (0.004 in)
Bolt (push lever shaft):
10 Nm (1.0 m•kg, 7.2
ft•lb)