Page 63 of 92

PERIODIC MAINTENANCE AND MINOR REPAIR
6-25
6
NOTE:Using 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.CAUTION:
ECA10570
Improper drive chain slack will over-
load the engine as well as other vital
parts of the motorcycle and can lead
to chain slippage or breakage. To
prevent this from occurring, keep
the drive chain slack within thespecified limits.3. Tighten the locknuts, and then
tighten the axle nut to the specified
torque.
EAU34311
To adjust the drive chain slack
(XT660X)
1. Loosen the axle nut and the lock-
nut on each side of the swingarm.
2. To tighten the drive chain, turn the
adjusting bolt on each side of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing bolt on each side of the
swingarm in direction (b), and then
push the rear wheel forward.NOTE:Using the alignment marks on each
side of the swingarm, make sure that
both chain pullers are in the same posi-tion for proper wheel alignment.
CAUTION:
ECA10570
Improper drive chain slack will over-
load the engine as well as other vital
parts of the motorcycle and can lead
to chain slippage or breakage. To
prevent this from occurring, keep
the drive chain slack within thespecified limits.
3. Tighten the locknuts, then the axle
nut to their specified torques.
1. Axle nut
2. Drive chain slack adjusting nut
3. Locknut
4. Alignment marks
Tightening torque:
Locknut:
16 Nm (1.6 m·kgf, 11 ft·lbf)
Axle nut:
104 Nm (10.4 m·kgf, 75 ft·lbf)
1. Axle nut
2. Drive chain slack adjusting bolt
3. Locknut
4. Alignment marks
4
3
12(a)
(b)
U5VKE1E0.book Page 25 Tuesday, July 18, 2006 1:00 PM
Page 75 of 92

PERIODIC MAINTENANCE AND MINOR REPAIR
6-37
6 4. Install the brake caliper by install-
ing the bolts.
NOTE:Make sure that there is enough space
between the brake pads before install-
ing the brake caliper onto the brakedisc.
5. Tighten the wheel axle to the spec-
ified torque.
6. Tighten the wheel axle pinch bolt A
and pinch bolt B to the specified
torques.
7. Retighten the wheel axle pinch bolt
A to the specified torque.
8. Tighten the brake caliper bolts to
the specified torques.
9. Push down hard on the handlebar
several times to check for proper
fork operation.
EAU25080
Rear wheel
EAUM1773
To remove the rear wheel
WARNING
EWA10820
It is advisable to have a Yamaha
dealer service the wheel.
Securely support the motor-
cycle so that there is no dangerof it falling over.
1. Remove the drive chain guard by
removing the bolts.
XT660RXT660X
2. Loosen the axle nut.
XT660R
Tightening torques:
Wheel axle:
59 Nm (5.9 m·kgf, 43 ft·lbf)
Front wheel axle pinch bolt:
18 Nm (1.8 m·kgf, 13 ft·lbf)
Brake caliper bolt:
40 Nm (4.0 m·kgf, 29 ft·lbf)
1. Bolt
2. Drive chain guard
1. Bolt
2. Drive chain guard
1. Axle nut
2. Drive chain slack adjusting nut
3. Locknut
4. Brake caliper bracket
5. Brake caliper
U5VKE1E0.book Page 37 Tuesday, July 18, 2006 1:00 PM
Page 77 of 92

PERIODIC MAINTENANCE AND MINOR REPAIR
6-39
6
XT660X: Install the washer on the
right-hand side.
Make sure that the retainer on the
swingarm is inserted into the slot in
the brake caliper bracket.
Make sure that there is enough
space between the brake pads be-fore installing the wheel.
3. Lower the rear wheel so that it is
on the ground.
4. Adjust the drive chain slack. (See
page 6-24.)
5. Tighten the axle nut to the speci-
fied torque.6. Install the drive chain guard by in-
stalling the bolts.
EAU25870
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.
1. Retainer
2. Slot
Tightening torque:
Locknut:
16 Nm (1.6 m·kgf, 11 ft·lbf)
Axle nut:
104 Nm (10.4 m·kgf, 75 ft·lbf)
U5VKE1E0.book Page 39 Tuesday, July 18, 2006 1:00 PM