Yamaha WR250F Owner's Service Manual page 291

NOTICE
After tightening the bolts, make sure that
the oil pump turns smoothly.
2. Install:
• Collar "1"
• Balancer weight gear "2"
TIP
Install the balancer weight gear and balancer
shaft with their lower splines "a" aligning with
each other.
1
2
3. Install:
• Balancer drive gear "1"
• Collar "2"
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
2
OIL PUMP AND BALANCER GEAR
4. Install:
• Conical washer "1"
• Balancer weight gear nut "2"
Balancer weight gear nut
50 Nm (5.0 m·kgf, 36 ft·lbf)
• Primary drive gear "3"
• Conical washer "4"
• Primary drive gear nut "5"
Primary drive gear nut
75 Nm (7.5 m·kgf, 54 ft·lbf)
• Balancer "6"
• Conical washer "7"
• Balancer nut "8"
Balancer nut
38 Nm (3.8 m·kgf, 27 ft·lbf)
TIP
• Apply engine oil to the contact surface and
threaded portion of the primary drive gear nut.
• Place an aluminum plate "a" between the
teeth of the balancer drive gear "9" and bal-
ancer weight gear "10".
• Install the conical washer with its convex sur-
face "b" outward.
• Align the balancer flat portion "c" with the flat
portion "d".
9
a
5
4
3
6-60
New
New
New
10
1
2
a
9
10
3
E
b 2
b 5