Removing The Balancer; Checking The Oil Pump; Assembling The Oil Pump - Yamaha YZ 2023 Series Owner's Service Manual

EAM30133

REMOVING THE BALANCER

1. Remove:
• Oil pump
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 1 1
4 4
2 2
4 4
3. Check:
• Primary drive gear "1"
• Balancer drive gear "2"
• Balancer weight gear "3"
Wear/damage  Replace.
5 5
a a a
a a a
3 3
5 5
5-61
1
4. Check:
• Balancer
Crack/damage  Replace.
EAM30136

CHECKING THE OIL PUMP

1. Check:
• Oil pump cover
• Oil pump drive shaft
• Oil pump housing
Cracks/damage/wear  Replace the oil
pump assembly.
2. Check:
• Oil pump operation
Rough movement  Repeat step (1) or re-
place the oil pump assembly.
EAM30137

ASSEMBLING THE OIL PUMP

1. Install:
• Oil pump drive shaft "1"
• Inner rotor "2"
• Dowel pin "3"
TIP
• Apply the engine oil on the oil pump drive shaft
and inner rotor.
• Fit the dowel pin into the groove in the inner ro-
tor.
OIL PUMP
2
3