Yamaha EXCITER, Service Manual

Page: 151 / 349

4-35
ENG
CYLINDER AND PISTON
3. Measure:
9
piston ring end gap
Out of specification
→
Replace the piston
ring.
NOTE:
The end gap of the oil ring expander cannot be
measured. If the end gaps of the oil ring rails
are excessive, replace all three piston rings.
EAS00265
CHECKING THE PISTON PIN
1. Check:
9
piston pin
Blue discoloration/grooves
→
Replace the
piston pin and then check the lubrication
system.
2. Measure:
9
piston pin outside diameter
a
Out of specification
→
Replace the piston
pin.
3. Measure:
9
piston pin bore diameter (of the piston)
b
Out of specification
→
Replace the piston.
Piston ring end gap
Top ring
0.10 – 0.25 mm
(0.0039 – 0.0098 in)
<Limit>: 0.4 mm (0.0157 in)
2nd ring
0.10 – 0.25 mm
(0.0039 – 0.0098 in)
<Limit>: 0.4 mm (0.0157 in)
Oil ring rails
0.20 – 0.70 mm (0.01 – 0.03 in)
Piston pin outside diameter
13.995 – 14.000 mm
(0.5510 – 0.5512 in)
<Limit>: 13.975 mm (0.5502 in)
Piston pin bore diameter (of the
piston)
14.002 – 14.013 mm
(0.5513 – 0.5517 in)
<Limit>: 14.043 mm (0.5529 in)
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