Checking The Piston Rings - Yamaha YJ125S Service Manual

CYLINDER AND PISTON
a
5-31
EAS00263

CHECKING THE PISTON RINGS

1. Measure:
8 piston ring side clearance
Out of specification
ton and piston rings as a set.
NOTE:
Before measuring the piston ring side clearance,
eliminate any carbon deposits from the piston
ring grooves and piston rings.
Piston ring side clearance
Top ring
0.02 ~ 0.08 mm(0.0008~0.0031 in)
<Limit>: 0.13mm(0.0051 in)
2nd ring
0.02 ~ 0.06 mm(0.0008~0.0024 in)
<Limit>:0.12 mm(0.0047 in)
2. Install:
8 piston ring
(into the cylinder)
NOTE:
Level the piston ring into the cylinder with the
piston crown.
a 20 mm (0.79 in)
3. Measure:
8 piston ring end gap
Out of specification
ton 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
Top ring
0.10 ~ 0.20 mm (0.004 ~ 0.008 in)
<Limit>: 0.45 mm (0.018 in)
2nd ring
0.20 ~ 0.30 mm (0.008 ~ 0.012 in)
<Limit>: 0.65 mm (0.026 in)
Oil ring
0.06 ~ 0.15 mm (0.002 ~ 0.006 in)
ENG
Replace the pis-
Replace the pis-