Page 57 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-19
6
WARNING
EWA10570
Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the
motorcycle with excessively
worn tires decreases riding sta-
bility and can lead to loss of
control.
The replacement of all wheel-
and brake-related parts, includ-
ing the tires, should be left to aYamaha dealer, who has the
necessary professional knowl-
edge and experience.
It is not recommended to patch
a punctured tube. If unavoid-
able, however, patch the tube
very carefully and replace it as
soon as possible with a high-quality product.
EAU21940
Spoke wheels To maximize the performance, durabil-
ity, and safe operation of your motor-
cycle, note the following points
regarding the specified wheels.
The wheel rims should be checked
for cracks, bends or warpage, and
the spokes for looseness or dam-
age before each ride. If any dam-
age is found, have a Yamaha
dealer replace the wheel. Do not
attempt even the smallest repair to
the wheel. A deformed or cracked
wheel must be replaced.
The wheel should be balanced
whenever either the tire or wheel
has been changed or replaced. An
unbalanced wheel can result in
poor performance, adverse han-
dling characteristics, and a short-
ened tire life.
Ride at moderate speeds after
changing a tire since the tire sur-
face must first be “broken in” for it
to develop its optimal characteris-
tics.
Front tire:
Size:
XT660R 90/90-21M/C 54S, 90/90-
21M/C 54T
XT660X 120/70R17 M/C 58H
Manufacturer/model:
XT660R METZELER/TOURANCE
FRONT
XT660X PIRELLI/DRAGON
XT660R MICHELIN/SIRAC
Rear tire:
Size:
XT660R 130/80-17M/C 65S,
130/80-17M/C 65T
XT660X 160/60R17 M/C 69H
Manufacturer/model:
XT660R METZELER/TOURANCE
XT660X PIRELLI/DRAGON
XT660R MICHELIN/SIRAC A
Page 58 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-20
6
EAU22041
Adjusting the clutch lever free
play The clutch lever free play should mea-
sure 10.0–15.0 mm (0.39–0.59 in) as
shown. Periodically check the clutch le-
ver free play and, if necessary, adjust it
as follows.
1. Loosen the locknut at the clutch le-
ver.
2. To increase the clutch lever free
play, turn the adjusting bolt in di-
rection (a). To decrease the clutch
lever free play, turn the adjusting
bolt in direction (b).
NOTE:If the specified clutch lever free play
could be obtained as described above,
tighten the locknut and skip the rest of
the procedure, otherwise proceed asfollows.
3. Fully turn the adjusting bolt at the
clutch lever in direction (a) to loos-
en the clutch cable.
4. Loosen the locknut at the crank-
case.5. To increase the clutch lever free
play, turn the adjusting nut in direc-
tion (a). To decrease the clutch le-
ver free play, turn the adjusting nut
in direction (b).
6. Tighten the locknut at the clutch le-
ver and the crankcase.
1. Locknut
2. Clutch lever free play adjusting bolt
3. Clutch lever free play
1. Locknut
2. Clutch lever free play adjusting nut
(crankcase)
Page 59 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-21
6
EAU22270
Adjusting the rear brake light
switch The rear brake light switch, which is ac-
tivated by the brake pedal, is properly
adjusted when the brake light comes
on just before braking takes effect. If
necessary, adjust the brake light switch
as follows.
Turn the adjusting nut while holding the
rear brake light switch in place. To
make the brake light come on earlier,
turn the adjusting nut in direction (a). To
make the brake light come on later, turn
the adjusting nut in direction (b).
EAU22390
Checking the front and rear
brake pads The front and rear brake pads must be
checked for wear at the intervals spec-
ified in the periodic maintenance and
lubrication chart.
EAU22430
Front brake pads
Each front brake pad is provided with
wear indicator grooves, which allow
you to check the brake pad wear with-
out having to disassemble the brake.
To check the brake pad wear, check
the wear indicator grooves. If a brake
pad has worn to the point that the wearindicator grooves have almost disap-
peared, have a Yamaha dealer replace
the brake pads as a set.
EAU22500
Rear brake pads
Check each rear brake pad for damage
and measure the lining thickness. If a
brake pad is damaged or if the lining
thickness is less than 1.0 mm (0.04 in),
have a Yamaha dealer replace the
brake pads as a set.
1. Rear brake light switch
2. Rear brake light switch adjusting nut
1. Brake pad wear indicator groove
1. Lining thickness
Page 60 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-22
6
EAU22580
Checking the brake fluid level Front brake
Rear brake
Insufficient brake fluid may allow air to
enter the brake system, possibly caus-
ing it to become ineffective.Before riding, check that the brake fluid
is above the minimum level mark and
replenish if necessary. A low brake fluid
level may indicate worn brake pads
and/or brake system leakage. If the
brake fluid level is low, be sure to check
the brake pads for wear and the brake
system for leakage.
Observe these precautions:
When checking the fluid level,
make sure that the top of the brake
fluid reservoir is level.
Use only the recommended quality
brake fluid, otherwise the rubber
seals may deteriorate, causing
leakage and poor braking perfor-
mance.
Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking performance.
Be careful that water does not en-
ter the brake fluid reservoir when
refilling. Water will significantly
lower the boiling point of the fluid
and may result in vapor lock.
Brake fluid may deteriorate paint-
ed surfaces or plastic parts. Al-
ways clean up spilled fluid
immediately.
As the brake pads wear, it is nor-
mal for the brake fluid level to grad-
ually go down. However, if the
brake fluid level goes down sud-
denly, have a Yamaha dealer
check the cause.
1. Minimum level mark
1. Minimum level mark
Recommended brake fluid:
DOT 4
Page 61 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-23
6
EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22780
To check the drive chain slack
1. Place the motorcycle on a level
surface and hold it in an upright po-
sition.NOTE:When checking and adjusting the drive
chain slack, the motorcycle should be
positioned straight up and there shouldbe no weight on it.
2. Shift the transmission into the neu-
tral position.3. Move the rear wheel by pushing
the motorcycle to locate the tight-
est portion of the drive chain, and
then measure the drive chain slack
as shown.
4. If the drive chain slack is incorrect,
adjust it as follows.
NOTE:When checking the drive chain slack,
the chain tensioner should not betouching the drive chain.
EAU22930
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
adjusting nut at each end of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing nut at each end 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 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.
1. Drive chain slack
Drive chain slack:
40.0–55.0 mm (1.57–2.17 in)
1. Axle nut
2. Drive chain slack adjusting nut
3. Locknut
4. Alignment marks
Page 62 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-24
63. Tighten the locknuts, and then
tighten the axle nut to the specified
torque.
EAU23021
Lubricating the drive chain The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.CAUTION:
ECA10581
The drive chain must be lubricated
after washing the motorcycle andriding in the rain.
1. Clean the drive chain with kero-
sene and a small soft brush.CAUTION:
ECA11120
To prevent damaging the O-rings, do
not clean the drive chain with steam
cleaners, high-pressure washers orinappropriate solvents.
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant.
CAUTION:
ECA11110
Do not use engine oil or any other lu-
bricants for the drive chain, as they
may contain substances that coulddamage the O-rings.
Tightening torque:
Axle nut:
104 Nm (10.4 m·kgf, 75 ft·lbf)
Page 63 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-25
6
EAU23100
Checking and lubricating the
cables The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING
EWA10720
Damage to the outer sheath may in-
terfere with proper cable operation
and will cause the inner cable to
rust. Replace a damaged cable as
soon as possible to prevent unsafeconditions.
EAU23110
Checking and lubricating the
throttle grip and cable The operation of the throttle grip should
be checked before each ride. In addi-
tion, the cable should be lubricated or
replaced at the intervals specified in the
periodic maintenance chart.
EAU23140
Checking and lubricating the
brake and clutch levers Brake lever
Clutch lever
The operation of the brake and clutch
levers should be checked before each
ride, and the lever pivots should be lu-
bricated if necessary.
Recommended lubricant:
Engine oil
Page 64 of 90
PERIODIC MAINTENANCE AND MINOR REPAIR
6-26
6
EAU23180
Lubricating the brake pedal The operation of the brake pedal
should be checked before each ride,
and the pedal pivot should be lubricat-
ed if necessary.
EAU23200
Checking and lubricating the
sidestand The operation of the sidestand should
be checked before each ride, and the
sidestand pivot and metal-to-metal
contact surfaces should be lubricated if
necessary.
WARNING
EWA10730
If the sidestand does not move up
and down smoothly, have a Yamahadealer check or repair it.
Recommended lubricant:
Lithium-soap-based grease (all-pur-
pose grease)
Recommended lubricant:
Lithium-soap-based grease (all-pur-
pose grease)
Recommended lubricant:
Lithium-soap-based grease (all-pur-
pose grease)