Yamaha YZ450FT Owner's Service Manual page 197

CRANKCASE AND CRANKSHAFT
Crankshaft
1. Remove:
Do not use a hammer to drive out the
crankshaft.
Crankshaft bearing
1. Remove:
NOTE:
• Remove the bearing from the crankcase by
• Do not use the removed bearing.
INSPECTION
Timing chain and timing chain guide
1. Inspect:
2. Inspect:
EC4N4101
Crankcase
1. Inspect:
2. Inspect:
3. Inspect:
4 - 89
• Crankshaft 1
Use the crankcase separating tool 2.
Crankcase separating tool:
YU-1135-A/90890-01135
CAUTION:
• Bearing 1
pressing its inner race.
• Timing chain
Cracks/stiff → Replace the timing chain
and camshaft sprocket as a set.
• Timing chain guide
Wear/damage → Replace.
• Contacting surface a
Scratches → Replace.
• Engine mounting boss b, crankcase
Cracks/damage → Replace.
• Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
• Oil seal
Wear/damage → Replace.
ENG