Checking The Piston Pin - Yamaha TW125 1999 Service Manual

CYLINDER AND PISTON
2. Install:
S piston ring
(into the cylinder)
NOTE:
Level the piston ring in the cylinder with the pis-
ton crown as shown.
a 5.0 mm
3. Measure:
S 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
EAS00265

CHECKING THE PISTON PIN

1. Check:
S piston pin
Blue discoloration/grooves ! Replace the
piston pin and then check the lubrication sys-
tem.
2. Measure:
S piston pin outside diameter a
Out of specification ! Replace the piston
pin.
Piston pin outside diameter
3. Calculate:
S piston-pin-to-piston clearance
Out of specification ! Replace the piston pin
and piston as a set.
4-27
ENG
Top ring
0.15 X 0.35 mm
<Limit>: 0.60 mm
2nd ring
0.15 X 0.35 mm
<Limit>: 0.60 mm
Oil ring
0.3 X 0.9 mm
14.987 X 14.992 mm