Cam Sprocket And Cam Drive Sprocket; Timing Chain Guide; Timing Chain Tensioner - Yamaha YFM250XL(C) Service Manual

INSPECTION AND REPAIR

CAM SPROCKET AND CAM DRIVE SPROCKET

1.Inspect:
Cam sprocket
Cam drive sprocket (crank shaft)
Wear/Damage → Replace cam sprocket
and timing chain as a set.
1 1/4 tooth
2 Correct
3 Roller
4 Sprocket

TIMING CHAIN GUIDE

1.Inspect:
Timing chain guide 1 (exhaust)
Timing chain guide 2 (intake)
Wear/Damage → Replace.

TIMING CHAIN TENSIONER

1.Inspect:
Chain tensioner rod 1
Gaskets 2
Damage/Wear → Replace.
2.Check:
Timing chain tensioner play
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Checking steps:
While pressing the tensioner rod lightly
with fingers, use a thin screwdriver 1 and
wind the tensioner rod up fully clockwise.
When releasing the screwdriver by press-
ing lightly with fingers, make sure that the
tensioner rod will come out smoothly.
If not, replace the tensioner assembly.
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ENG
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