YAMAHA XT660X 2008 Repair Manual

PERIODIC MAINTENANCE AND MINOR REPAIR
6-23
6 indicator 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.
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.
1. Lining thickness
1. Minimum level mark
1. Minimum level mark
Recommended brake fluid:
DOT 4
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-24
6


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.
EAU22760
Drive chain slack The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22782
To check the drive chain slack
1. Place the motorcycle on the side-
stand.NOTE:When checking and adjusting the drive
chain slack, there should be no weighton the motorcycle.
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.
EAU22932
To adjust the drive chain slack
(XT660R)
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.
1. Drive chain slack
Drive chain slack:
40.0–55.0 mm (1.57–2.17 in)
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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)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-26
6
EAU23022
Cleaning and 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 torques:
Locknut:
16 Nm (1.6 m·kgf, 11 ft·lbf)
Axle nut:
104 Nm (10.4 m·kgf, 75 ft·lbf)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-27
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.
EAU23111
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 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
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-28
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)
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-29
6
EAU23271
Checking the front fork The condition and operation of the front
fork must be checked as follows at the
intervals specified in the periodic main-
tenance and lubrication chart.
To check the condition
WARNING
EWA10750
Securely support the vehicle so thatthere is no danger of it falling over.
Check the inner tubes for scratches,
damage and excessive oil leakage.
To check the operation
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
2. While applying the front brake,
push down hard on the handlebars
several times to check if the front
fork compresses and rebounds
smoothly.
CAUTION:
ECA10590
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or re-pair it.
EAU23280
Checking the steering Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the pe-
riodic maintenance and lubrication
chart.
1. Place a stand under the engine to
raise the front wheel off the
ground.
WARNING
EWA10750
Securely support the vehicle so thatthere is no danger of it falling over.
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steering.
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-30
6
EAU23290
Checking the wheel bearings The front and rear wheel bearings must
be checked at the intervals specified in
the periodic maintenance and lubrica-
tion chart. If there is play in the wheel
hub or if the wheel does not turn
smoothly, have a Yamaha dealer check
the wheel bearings.
EAUM1730
Battery This model is equipped with a sealed-
type (MF) battery, which does not re-
quire any maintenance. There is no
need to check the electrolyte or to add
distilled water.CAUTION:
ECA10620
Never attempt to remove the battery
cell seals, as this would permanent-ly damage the battery.
To access the battery
1. Remove the seat. (See page
3-12.)
2. Remove the battery cover by re-
moving the bolts.
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-31
6 To charge the battery
Have a Yamaha dealer charge the bat-
tery as soon as possible if it seems to
have discharged. Keep in mind that the
battery tends to discharge more quickly
if the vehicle is equipped with optional
electrical accessories.
WARNING
EWA10760


Electrolyte is poisonous and
dangerous since it contains sul-
furic acid, which causes severe
burns. Avoid any contact with
skin, eyes or clothing and al-
ways shield your eyes whenworking near batteries. In case
of contact, administer the fol-
lowing FIRST AID.
EXTERNAL: Flush with plenty
of water.
INTERNAL: Drink large quan-
tities of water or milk and im-
mediately call a physician.
EYES: Flush with water for 15
minutes and seek prompt
medical attention.


Batteries produce explosive hy-
drogen gas. Therefore, keep
sparks, flames, cigarettes, etc.,
away from the battery and pro-
vide sufficient ventilation when
charging it in an enclosed
space.


KEEP THIS AND ALL BATTER-
IES OUT OF THE REACH OFCHILDREN.
To store the battery
1. If the vehicle will not be used for
more than one month, remove the
battery, fully charge it, and then
place it in a cool, dry place.2. If the battery will be stored for more
than two months, check it at least
once a month and fully charge it if
necessary.
3. Fully charge the battery before in-
stallation.
4. After installation, make sure that
the battery leads are properly con-
nected to the battery terminals.
CAUTION:
ECA10630


Always keep the battery
charged. Storing a discharged
battery can cause permanent
battery damage.


To charge a sealed-type (MF)
battery, a special (constant-volt-
age) battery charger is required.
Using a conventional battery
charger will damage the battery.
If you do not have access to a
sealed-type (MF) battery charg-
er, have a Yamaha dealercharge your battery.
1. Negative battery terminal
2. Positive battery terminal
3. Bolt
4. Battery cover
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PERIODIC MAINTENANCE AND MINOR REPAIR
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6
EAUM1740
Replacing the fuses The main fuse is located behind panel
A. (See page 6-5.)
Fuse box 1 and fuse box 2 are located
under the seat. (See page 3-12.)
If a fuse is blown, replace it as follows.
1. Turn the key to “OFF” and turn off
the electrical circuit in question.
2. Remove the blown fuse, and then
install a new fuse of the specified
amperage.
CAUTION:
ECA10640
Do not use a fuse of a higher amper-
age rating than recommended to
avoid causing extensive damage to
the electrical system and possibly afire.
3. Turn the key to “ON” and turn on
the electrical circuit in question to
check if the device operates.
1. Main fuse
2. Spare main fuse
1. Fuse box 1
2. Signaling system fuse
3. Headlight fuse
4. Ignition fuse
5. Fuel injection system fuse
6. Radiator fan fuse
7. Backup fuse (for odometer, clock and immo-
bilizer system)
8. Parking lighting fuse
9. Fuse box 2
10.Spare fuse
Specified fuses:
Main fuse:
30.0 A
Fuse box 1:
Headlight fuse:
20.0 A
Signaling system fuse:
10.0 A
Radiator fan fuse:
7.5 A
Ignition fuse:
10.0 A
Fuel injection system fuse:
10.0 A
Backup fuse:
10.0 A
Fuse box 2:
Parking lighting fuse:
10.0 A
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