Checking The Piston Pin - Yamaha YFM700RV 2009 Service Manual

CYLINDER AND PISTON
3. Measure:
• piston ring end gap
Out of specification → Replace the piston
ring.
NOTE:
_
The oil ring expander spacer's end gap cannot
be measured. If the oil ring rail's gap is exces-
sive, replace all three piston rings.
Piston ring end gap
EBS00251

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
4 - 37
ENG
Top ring
0.20 ~ 0.35 mm
(0.008 ~ 0.014 in)
<Limit>: 0.60 mm (0.024 in)
2nd ring
0.35 ~ 0.50 mm
(0.014 ~ 0.020 in)
<Limit>: 0.85 mm (0.033 in)
Oil ring
0.20 ~ 0.70 mm
(0.008 ~ 0.028 in)
22.991 ~ 23.000 mm
(0.9052 ~ 0.9055 in)
<Limit>: 22.971 mm (0.9044 in)