Yamaha 2008 Raptor 250, Service Manual

Page: 152 / 311

ENG
4-36
CHECKING THE PISTON PIN
1. Check:
• Piston pin
Blue discoloration/grooves
→
Replace the
piston pin and then check the lubrication
system.
2. Measure:
• Piston pin outside diameter
Out of specification
→
Replace the piston
pin.
3. Measure:
• Piston pin bore diameter
Out of specification
→
Replace the piston.
4. Calculate:
• Piston-pin-to-piston-pin-bore clearance
Out of specification
→
Replace the piston
pin and piston as a set.
Piston pin outside diameter
16.991 ~ 17.000 mm
(0.6689 ~ 0.6693 in)
Limit
16.971 mm (0.6681 in)
Piston pin bore inside diameter
17.002 ~ 17.013 mm
(0.6694 ~ 0.6698 in)
Limit
17.043 mm (0.6710 in)
Piston-pin-to-piston-pin-bore clearance =
Piston pin bore diameter
-
Piston pin outside diameter
Piston-pin-to-piston-pin-bore
clearance
0.002 ~ 0.022 mm
(0.0001 ~ 0.0009 in)
Limit
0.072 mm (0.0028 in)
CYLINDER AND PISTON