Yamaha YZ450F 2020 Owner's Service Manual page 253

Oil pump assembly bolt
5 N·m (0.5 kgf·m, 3.7 lb·ft)
LOCTITE®
LT
2 2
ECA13890
NOTICE
After tightening the bolts, make sure the oil
pump turns smoothly.
2. Install:
• Balancer weight gear "1"
TIP
Install the balancer weight gear and balancer
shaft with their lower splines "a" aligning with
each other.
1 1
3. Install:
• Balancer drive gear "1"
TIP
• Align the punched mark "a" on the balancer
drive gear with the punched mark "b" on the
balancer weight gear.
• Install the balancer drive gear and crankshaft
with the lower splines "c" aligning with each
other.
1 1 1
a c
5-63
1 1
4. Install:
• Lock washer "1"
New
• Balancer weight gear nut "2"
Balancer weight gear nut
50 N·m (5.0 kgf·m, 37 lb·ft)
• Primary drive gear "3"
• Conical washer "4"
• Primary drive gear nut "5"
Primary drive gear nut
80 N·m (8.0 kgf·m, 59 lb·ft)
• Straight key "6"
• Balancer "7"
• Lock washer "8"
New
• Balancer nut "9"
Balancer nut
45 N·m (4.5 kgf·m, 33 lb·ft)
TIP
• Apply engine oil to the contact surface and
threaded portion of the primary drive gear nut.
• Apply engine oil to the contact surfaces of the
conical washer.
• Place an aluminum plate "a" between the teeth
of the balancer drive gear "10" and balancer
weight gear "11".
• Install the conical washer with its convex sur-
face "b" outward.
4 4
5 5
OIL PUMP
a a
b b
c c
New
11 11 11
1 1
2 2
a a