Yamaha YZ450FP 2023, Owner'S Service Manual

Page: 257 / 388

STARTER CLUTCH
5-61
EAM30624
REMOVING THE BALANCER GEAR
1. Straighten the lock washer tab.
2. Loosen:
• Balancer driven gear nut “1”
•
Primary drive gear nut “2”
TIP
Place an aluminum plate “a” between the teeth
of the balancer drive gear “3” and balancer driv-
en gear “4”.
3. Check:
• Primary drive gear “1”
•
Starter reduction gear “2”
• Balancer drive gear “3”
•
Balancer driven gear “4”
• Oil pump drive gear “5”
Wear/damage

Replace.
EAM30140
CHECKING THE STARTER CLUTCH
1. Remove:
•
Starter clutch assembly
Refer to “OIL PUMP” on page 5-63.
2. Check:
• Starter clutch assembly
Burrs/chips/roughness/wear

Replace the
starter clutch assembly.
3. Check:
•
Starter clutch operation
a. Install the starter clutch onto the balancer
drive gear “1”, and then install onto the
starter reduction gear “2”.
b. When turning the balancer drive gear
counterclockwise “A”, it should turn freely,
otherwise the starter clutch is faulty and
must be replaced.
c. When turning the balancer drive gear
clockwise “B”, the starter clutch and the
balancer drive gear should engage, other-
wise the starter clutch is faulty and must
be replaced.
EAM30630
INSTALLING THE BALANCER GEAR
1. Install:
•
Oil pump drive gear
• Balancer driven gear “1”
TIP
Install the balancer driven gear and balancer
shaft with their lower splines “a” aligning with
each other.
2 2 2
a a
1 1
3 3
4 4
2 2 2
3 3
a a
4 4
1 1
1
2
3
4
5
1
2
A A A
B B