Yamaha WR250FM service manual Cylinder

CYLINDER AND PISTON

ENG

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45˚

135˚135˚

cbe

3 New

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 New

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:

•Piston

•Piston ring

•Cylinder

NOTE:

Apply a liberal coating of engine oil.

2.Install:

•Dowel pin 1

•O-ring 2 New

NOTE:

Apply the lithium soap base grease on the O- ring.

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