Yamaha WR250F(N), Owner'S Service Manual

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ENG
CYLINDER AND PISTON
2. Position:
●
Top ring
●
2nd ring
●
Oil ring
Offset the piston ring end gaps as
shown.
a
Top ring end
b
2nd ring end
c
Oil ring end (upper)
d
Oil ring
e
Oil ring end (lower)
3. Install:
●
Piston 1
●
Piston pin
2
●
Piston pin clip 3
NOTE:
●
Apply engine oil onto the piston pin and pis-
ton.
●
Be sure that the arrow mark
a
on the piston
points to the exhaust side of the engine.
●
Before installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase.
●
Install the piston pin clips with their ends fac-
ing downward.
45
°
135
°
135
°
a
b c e
d
3
New
Cylinder
1. Lubricate:
●
Piston
●
Piston ring
●
Cylinder
NOTE:
Apply a liberal coating of engine oil.
2. Install:
●
Dowel pin 1
●
O-ring 2
NOTE:
Apply the lithium soap base grease on the O-
ring.