Yamaha YZ450F(W), Owner'S Service Manual

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4 - 65
ENG
BALANCER
ASSEMBLY AND INSTALLATION
Balancer, balancer drive gear and balancer
driven gear
1. Install:
• Balancer driven gear
1
NOTE:
Install the balancer driven gear and balancer
shaft with their lower splines
a
aligning with
each other.
2. Install:
• Balancer drive gear
1
NOTE:
• Align the punched mark
a
on the balancer
drive gear with the punched mark
b
on the
balancer driven gear.
• Install the balancer driven gear and crank-
shaft with the lower splines
c
aligning with
each other.
3. Install:
• Lock washer
1
• Nut (balancer driven gear)
2
• Primary drive gear
3
• Conical washer
4
• Nut (primary drive gear)
5
• Straight key
6
• Balancer
7
• Lock washer
8
• Nut (balancer)
9
NOTE:
• Apply engine oil to the contact surface and
threaded portion of the nut (primary drive
gear).
• Place an aluminum plate
a
between the
teeth of the balancer drive gear
0
and bal-
ancer driven gear
A
.
• Install the primary drive gear with its weight
reduction holes
b
facing the engine.
• Install the conical washer with its convex sur-
face
c
outward.
4. Bend the lock washer tab.
a
0
1
A
2
T
R
.
.
50 Nm (5.0 m · kg, 36 ft · lb)
E
A
0
a
c
b
5
4
3
T
R
.
.
110 Nm (11.0 m · kg, 80 ft · lb)
T
R
.
.
45 Nm (4.5 m · kg, 33 ft · lb)