Yamaha YZ450FF 1SL-28199-11, Owner'S Service Manual

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CRANKSHAFT ASSEMBLY AND BALANCER SHAFT
5-69
EAS1SL5286
REMOVING THE BALANCER SHAFT
1. Remove:
• Balancer shaft “1”
TIP
Remove the balancer shaft with its flat side “a”
facing the crankshaft.
EAS1SL5287 REMOVING THE CRANKSHAFT ASSEMBLY
1. Remove:
• Crankshaft assembly “1”
TIP
Remove the crankshaft assembly by using the
crankcase separating tool “2”.
EAS1SL5288
CHECKING THE CRANKSHAFT ASSEMBLY
1. Measure:
• Crankshaft runout
Out of specification

Replace the crank-
shaft, bearing or both.
TIP
Turn the crankshaft slowly.
2. Measure:
• Big end side clearance D “a”
Out of specification

Replace the big end
bearing, crankshaft pin, or connecting rod.
3. Measure:
• Crankshaft width A “a”
Out of specification

Replace the crank-
shaft.
Crankcase separating tool
90890-04152
YU-A9642
1
a
2
1
Runout limit C
0.030 mm (0.0012 in)
Big end side clearance D
0.150–0.450 mm (0.0059–0.0177
in)
Width A
61.95–62.00 mm (2.439–2.441 in)