Checking The Timing Chain And Guide; Checking The Bearings And Oil Seals; Checking The Crankcase - Yamaha YFZ450S 2003 Service Manual

CRANKCASE
2. Check:
• oil delivery pipe 2
Cracks/damage → Replace.
• oil delivery pipe holes 1
Clogged → Blow out with compressed air.
EBS00335

CHECKING THE TIMING CHAIN AND GUIDE

1. Check:
• timing chain
Cracks/stiffness → Replace the timing
chain and camshaft as a set.
2. Check:
• timing chain guide (intake side)
Wear/damage → Replace.
EBS00339
CHECKING THE BEARINGS AND OIL
SEALS
1. Check:
• bearings
Clean and lubricate, then rotate the inner
race with a finger.
Roughness → Replace.
2. Check:
• oil seals
Damage/wear → Replace.
EBS00338

CHECKING THE CRANKCASE

1. Thoroughly wash the case halves in a mild
solvent.
2. Clean all the gasket mating surfaces and
crankcase mating surfaces thoroughly.
3. Check:
• crankcase
Cracks/damage → Replace.
• oil delivery passages
Clogged → Blow out with compressed air.
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