Yamaha YZ250F(R) Owner's Service Manual page 151

a d
45°
135° 135°
c b
3
CYLINDER AND PISTON
2. Position:
a Top ring end
b 2nd ring end
c Oil ring end (upper)
e
d Oil ring
e Oil ring end (lower)
3. Install:
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.
Cylinder
1. Lubricate:
NOTE:
Apply a liberal coating of engine oil.
2. Install:
NOTE:
Apply the lithium soap base grease on the O-
ring.
4 - 47
ENG
Top ring
●
2nd ring
●
Oil ring
●
Offset the piston ring end gaps as
shown.
Piston 1
●
Piston pin 2
●
Piston pin clip 3
●
Piston
●
Piston ring
●
Cylinder
●
Dowel pin 1
●
O-ring 2
●