Removing The Crankshaft; Checking The Crankshaft - Yamaha YZ 2020 Series Owner's Service Manual

EAM30491

REMOVING THE CRANKSHAFT

1. Remove:
• Balancer shaft "1"
TIP
Remove the balancer shaft with its flat side "a"
facing the crankshaft.
2. Remove:
• Crankshaft assembly "1"
TIP
Remove the crankshaft assembly by using the
crankcase separating tool "2".
Crankcase separating tool
90890-04152
Crankcase separating tool
YU-A9642
1
EAM30492

CHECKING THE CRANKSHAFT

1. Measure:
• Crankshaft runout
CRANKSHAFT AND BALANCER SHAFT
Out of specification  Replace the crank-
shaft, bearing or both.
TIP
Turn the crankshaft slowly.
1
a a
2. Measure:
• Crank assembly width "a"
Out of specification  Replace the crank-
shaft.
2
3. Check:
• Crankshaft sprocket "1"
Damage  Replace the crankshaft.
4. Check:
• Crankshaft journal oil passage
Obstruction  Blow out with compressed air.
5-71
Runout limit
0.030 mm (0.0012 in)
Crank assembly width
55.93–56.00 mm (2.202–2.205 in)
1