Yamaha YZ250F Owner's Service Manual page 164

BALANCER
REMOVAL POINTS
Balancer shaft drive gear and balancer
shaft driven gear
1. Straighten the lock washer tab.
2. Loosen:
• Nut (primary drive gear) 1
• Nut (balancer shaft driven gear) 2
NOTE:
Place an aluminum plate a between the teeth
of the balancer shaft drive gear 3 and driven
gear 4.
Balancer shaft
1. Remove:
• Balancer shaft 1
NOTE:
When removing the balancer shaft, align the
center a of the balancer shaft weight along
the line connecting the centers of the crank-
shaft and balancer shaft.
INSPECTION
Primary drive gear, balancer shaft drive
gear and balancer shaft driven gear
1. Inspect:
• Primary drive gear 1
• Balancer shaft drive gear 2
• Balancer shaft driven gear 3
Wear/damage → Replace.
Balancer shaft
1. Inspect:
• Balancer shaft
Cracks/damage → Replace.
4 - 64
ENG