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PERIODIC MAINTENANCE AND ADJUSTMENT
6-22
64. If the drive chain slack is incorrect,
adjust it as follows.
EAU22934
To adjust the drive chain slack
1. Loosen the axle nut, then loosen
the locknut at each end of the
swingarm.
2. To tighten the drive chain, turn the
drive chain slack adjusting nut at
each end of the swingarm in direc-
tion (a). To loosen the drive chain,
turn the adjusting nut at each end
of the swingarm in direction (b),
and then push the rear wheel for-
ward. NOTICE: Improper drive
chain slack will overload the en-
gine as well as other vital partsof the motorcycle and can lead
to chain slippage or breakage.
To prevent this from occurring,
keep the drive chain slack with-
in the specified limits.
[ECA10571]
TIPUsing the alignment marks on each
side of the swingarm, make sure that
both adjusting nuts are in the same po-sition for proper wheel alignment.
3. Tighten the locknuts, and then
tighten the axle nut to the specified
torques.
1. Drive chain slack
1. Axle nut
2. Drive chain slack adjusting nut
3. Locknut
4. Alignment marks
Tightening torques:
Locknut:
16 Nm (1.6 m·kgf, 11 ft·lbf)
Axle nut:
90 Nm (9.0 m·kgf, 65 ft·lbf)
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-33
6 2. Lift the front wheel off the ground
according to the procedure on
page 6-32.
3. Remove the speed sensor lead
holder by removing the screw
(WR125R only).
4. Remove the brake caliper by re-
moving the bolts.
5. Pull the wheel axle out, remove the
speed sensor by pulling it out, and
then remove the wheel. NOTICE:
Do not apply the brake after the
brake calipers have been re-
moved, otherwise the brake
pads will be forced shut.
[ECA11051]EAUM2640
To install the front wheel
1. Lift the wheel up between the fork
legs.
2. Install the speed sensor at the
wheel hub.TIPMake sure that the projections on the
speed sensor rotor are aligned with the
notches in the wheel hub and that the
slot in the speed sensor fits over the re-tainer on the fork leg.
3. Insert the wheel axle.
4. Lower the front wheel so that it is
on the ground.5. Push down hard on the handlebar
several times to check for proper
fork operation.
6. Install the brake caliper by install-
ing the bolts.
TIPMake sure that there is enough space
between the brake pads before install-
ing the brake caliper onto the brakedisc.
7. Install the speed sensor lead hold-
er by installing the screw
(WR125R only).
8. Tighten the wheel axle, front wheel
axle pinch bolts and brake caliper
bolts to their specified torques.
1. Brake caliper
2. Brake caliper bolt
1. Speed sensor
Tightening torques:
Wheel axle:
58 Nm (5.8 m·kgf, 42 ft·lbf)
Front wheel axle pinch bolt:
9 Nm (0.9 m·kgf, 6.5 ft·lbf)
Brake caliper bolt:
30 Nm (3.0 m·kgf, 22 ft·lbf)
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-35
6 2. Install the wheel, the drive chain
alignment plates and the brake
caliper bracket by inserting the
wheel axle from the right-hand
side.
TIP
Install the drive chain alignment
plate with the “N” mark on the left
side, and be sure the mark is fac-
ing outward.
Make sure that the slot in the brake
caliper bracket is fit over the retain-
er on the swingarm.
Make sure that there is enough
space between the brake pads be-fore installing the wheel.3. Install the axle nut.
4. Lower the rear wheel so that it is
on the ground.
5. Adjust the drive chain slack. (See
page 6-21.)
6. Tighten the axle nut to the speci-
fied torque.
EAU25871
Troubleshooting Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur dur-
ing operation. Any problem in the fuel,
compression, or ignition systems, for
example, can cause poor starting and
loss of power.
The following troubleshooting charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your motorcycle
require any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the motorcycle
properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look like
Yamaha parts, but they are often inferi-
or, have a shorter service life and can
lead to expensive repair bills.
WARNING
EWA15141
When checking the fuel system, do
not smoke, and make sure there are
no open flames or sparks in the ar-
ea, including pilot lights from water
1. Retainer
2. Slot
Tightening torque:
Axle nut:
90 Nm (9.0 m·kgf, 65 ft·lbf)
U22BE0E0.book Page 35 Wednesday, December 17, 2008 11:00 AM