Yamaha YZ250F(T) Owner's Service Manual page 436

CRANKCASE AND CRANKSHAFT
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Crankshaft
1. Remove:
• Crankshaft 1
Use the crankcase separating tool 2.
Crankcase separating tool:
YU-1135-A/90890-01135
CAUTION:
Do not use a hammer to drive out the
crankshaft.
Crankcase bearing
1. Remove:
• Bearing 1
NOTE:
• Remove the bearing from the crankcase by
pressing its inner race.
• Do not use the removed bearing.
INSPECTION
Timing chain and timing chain guide
1. Inspect:
• Timing chain
Cracks/stiff → Replace the timing chain
and camshaft sprocket as a set.
2. Inspect:
• Timing chain guide
Wear/damage → Replace.
Crankcase
1. Inspect:
• Contacting surface a
Scratches → Replace.
• Engine mounting boss b, crankcase
Cracks/damage → Replace.
2. Inspect:
• Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
3. Inspect:
• Oil seal
Damage → Replace.
ENG