Oil Pump And Balancer Gear; Removing The Balancer; Checking The Primary Drive Gear, Balancer Drive Gear, And Balancer Weight Gear; Checking The Balancer - Yamaha YZ450FX 2019 Owner's Service Manual

EAM30133

REMOVING THE BALANCER

1. Straighten the lock washer tab.
2. 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".
4 4
2 2
4 4 4
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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.

OIL PUMP AND BALANCER GEAR

1 1 1
5 5
a a
a a
3 3
5 5
5-54
1 1 1
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CHECKING THE BALANCER

1. Check:
• Balancer
Crack/damage  Replace.
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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
"b"
• Oil-pump-housing-to-inner-rotor-and-outer-
rotor clearance "c"
Out of specification  Replace the oil pump.
Inner-rotor-to-outer-rotor-tip
clearance
0.000–0.150 mm (0.0000–0.0059
in)
Oil-pump-housing-to-inner-and-
outer-rotor clearance
0.06–0.11 mm (0.0024–0.0043 in)
Limit
0.18 mm (0.0071 in)
2 2
3 3
clearance