Yamaha YZ 2017 Series, Owner'S Service Manual, Page: 259 / 410

OIL PUMP AND BALANCER GEAR
5-58
EASB29B265
REMOVING THE BALANCER
1. Loosen:
• Balancer nut “1”
• Primary drive gear nut “2”
• Balancer weight gear nut “3”
TIP
Place an aluminum plate “a” between the teeth
of the balancer drive gear “4” and balancer
weight gear “5”.
EASB29B266 CHECKING THE PRIMARY DRIVE GEAR,
BALANCER DRIVE GEAR, AND BALANCER
WEIGHT GEAR
1. Check:
• Primary drive gear “1”
• Balancer drive gear “2”
• Balancer weight gear “3”
Wear/damage

Replace.
EASB29B267 CHECKING THE BALANCER
1. Check:
• Balancer
Crack/damage

Replace.
EASB29B268 CHECKING THE OIL PUMP
1. Check:
• Oil pump cover
• Oil pump drive shaft
• Oil pump housing
Cracks/damage/wear

Replace the defec-
tive part(s).
2. Measure:
• Inner-rotor-to-outer-rotor-tip clearance “a”
• Outer-rotor-to-oil-pump-housing clearance
“b”
• Oil-pump-housing-to-inner-rotor-and-outer-
rotor clearance “c”
Out of specification

Replace the oil pump.
1
4
a
5
2
4
a
5
3