Removing The Balancer; Checking The Primary Drive Gear, Balancer Shaft Drive Gear, And Balancer Weight Gear; Checking The Balancer; Checking The Oil Pump - Yamaha YZ450F Owner's Service Manual

REMOVING THE BALANCER

EAS1SL5267
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".
1
4
2
4
a
EAS1SL5268 CHECKING THE PRIMARY DRIVE GEAR,
BALANCER SHAFT DRIVE GEAR, AND
BALANCER WEIGHT GEAR
1. Check:
• Primary drive gear "1"
• Balancer shaft drive gear "2"
• Balancer weight gear "3"
Wear/damage  Replace.
OIL PUMP AND BALANCER GEAR
5
a
3
5

CHECKING THE BALANCER

EAS1SL5269
1. Check:
• Balancer
Crack/damage  Replace.

CHECKING THE OIL PUMP

EAS1SL5270
1. Check:
• Oil pump drive gear
• Oil pump driven gear
• Oil pump housing
• Oil pump housing cover
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.
Inner-rotor-to-outer-rotor-tip
clearance
Less than
0.150 mm (0.0059 in)
Outer-rotor-to-oil-pump-housing
clearance
0.13–0.18 mm (0.0051–0.0071 in)
Oil-pump-housing-to-inner-and-
outer-rotor
clearance
0.06–0.11 mm (0.0024–0.0043 in)
5-56