Yamaha XT660R, Service Manual

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ENG
CYLINDER AND PISTON
EAS00265
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
a
Out of specification
→
Replace the piston
pin.
Piston pin outside diameter
22.991 ~ 23.000 mm
(0.9052 ~ 0.9055 in)
<Limit>: 22.971 mm (0.9044 in)
3. Measure:
• piston pin bore inside diameter
b
Out of specification
→
Replace the piston.
Piston pin bore inside diameter
23.004 ~ 23.015 mm
(0.9057 ~ 0.9061 in)
<Limit>: 23.045 mm (0.9073 in)
4. Calculate:
• piston-pin-to-piston-pin-bore clearance
Out of specification
→
Replace the piston
pin and piston as a set.
Piston-pin-to-piston-pin-bore clearance =
Piston pin bore inside diameter
b
–
Piston pin outside diameter
a
Piston-pin-to-piston clearance
0.004 ~ 0.024 mm
(0.0002 ~ 0.0009 in)
<Limit>: 0.074 mm (0.0029 in)