2006 YAMAHA WR 450F weight

4 - 66
ENGBALANCER
REMOVAL POINTS
Balancer drive gear and balancer driven
gear
1. Straighten the lock washer tab.
2. Loosen:
Nut (primary drive gear) 1
Nut (balancer) 2
NOTE:
Place an aluminum plate a between the teeth
of the balancer drive gear 3 and driven gear
4.
a 3
14
2
4 3
a
Balancer
1. Remove:
Balancer 1
NOTE:
When removing the balancer shaft, align the
center of the balancer shaft weight a along
the line connecting the centers of the crank-
shaft and balancer shaft.
INSPECTION
Primary drive gear, balancer drive gear and
balancer driven gear
1. Inspect:
Primary drive gear 1
Balancer drive gear 2
Balancer driven gear 3
Wear/damage → Replace.
Balancer
1. Inspect:
Balancer
Cracks/damage → Replace.

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ENGBALANCER
ASSEMBLY AND INSTALLATION
Balancer, balancer drive gear and balancer
driven gear
1. Install:
Balancer 1
NOTE:
When installing the balancer shaft, align the
center of the balancer shaft weight a along
the line connecting the centers of the crank-
shaft and balancer shaft.
2. Install:
Balancer driven gear 1
NOTE:
Install the balancer driven gear onto the bal-
ancer while aligning the punch mark a on the
balancer driven gear with the lower spline b
on the balancer end.
3. 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.
Align the punched mark c on the balancer
drive gear with the lower spline d on the
crankshaft.
4. Install:
Lock washer 1
Nut (balancer) 2
Primary drive gear 3
Conical washer 4
Nut (primary drive gear) 5
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 6 and driven
gear 7.
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.
5. Bend the lock washer tab.
a 6
17
2
T R..50 Nm (5.0 m · kg, 36 ft · lb)
T R..110 Nm (11.0 m · kg, 80 ft · lb)
E
7
6a
c b
5
4
3

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TUN
EC72A001
Setting of spring after replacement
As the front fork setting can be easily affected
by rear suspension, take care so that the
machine front and rear are balanced (in posi-
tion, etc.) when setting the front fork.
1. Use of soft spring
Generally a soft spring gives a soft riding
feeling. Rebound damping tends to
become stronger and the front fork may
sink deeply over a series of gaps.
To set a soft spring:
•Change the rebound damping.
Turn out one or two clicks.
•Change the compression damping.
Turn in one or two clicks.
2. Use of stiff spring
Generally a stiff spring gives a stiff riding
feeling. Rebound damping tends to
become weaker, resulting in lack of a
sense of contact with the road surface or in
a vibrating handlebar.
To set a stiff spring:
•Change the rebound damping.
Turn in one or two clicks.
•Change the compression damping.
Turn out one or two clicks.
ÈCoverage of spring by weight
ÉRider weight
1Soft
2Standard
3Stiff
SETTING

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TUN
CAUTION:
When using a rear cushion other than cur-
rently installed, use the one whose overall
length a does not exceed the standard as
it may result in faulty performance. Never
use one whose overall length is greater
than standard.
ÈCoverage of spring by weight
ÉRider weight
1Soft
2Standard
3Stiff
Length a of standard shock:
487.5 mm (19.19 in)
SETTING