Page 67 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-29
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
Page 68 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-30
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. Electronic fuel injection fuse
6. Radiator fan fuse
7. Backup fuse (for odometer, clock and
immobilizer 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
Electronic fuel injection fuse:
10.0 A
Backup fuse:
10.0 A
Fuse box 2:
Parking lighting fuse:
10.0 A
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-31
6 4. If the fuse immediately blows
again, have a Yamaha dealer
check the electrical system.
EAUM1750
Replacing the headlight bulb This model is equipped with a quartz
bulb headlight. If the headlight bulb
burns out, replace it as follows.
1. Remove cowling A together with
the headlight unit. (See page 6-5.)
2. Disconnect the headlight coupler,
and then remove the headlight
bulb cover.
3. Remove the headlight bulb holder
by turning it counterclockwise, and
then remove the defective bulb.
WARNING
EWA10790
Headlight bulbs get very hot. There-
fore, keep flammable products away
from a lit headlight bulb, and do not
touch the bulb until it has cooleddown.
4. Place a new bulb into position, and
then secure it with the bulb holder.CAUTION:
ECA10660
Do not touch the glass part of the
headlight bulb to keep it free from
oil, otherwise the transparency of
the glass, the luminosity of the bulb,
and the bulb life will be adversely af-
1. Headlight bulb cover
2. Headlight coupler
1. Headlight bulb holder
2. Headlight bulb
Page 70 of 90
PERIODIC MAINTENANCE AND MINOR REPAIR
6-32
6fected. Thoroughly clean off any dirt
and fingerprints on the headlight
bulb using a cloth moistened with al-
cohol or thinner.
5. Install the bulb cover, and then
connect the coupler.
6. Install the cowling together with
the headlight unit.
7. Have a Yamaha dealer adjust the
headlight beam if necessary.
EAU24281
Replacing a turn signal light
bulb or the tail/brake light bulb 1. Remove the lens by removing the
screws.2. Remove the defective bulb by
pushing it in and turning it counter-
clockwise.
3. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.
4. Install the lens by installing the
screws.
CAUTION:
ECA10680
Do not overtighten the screws, oth-erwise the lens may break.
1. Do not touch the glass part of the bulb.
1. Screw
1. Screw
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PERIODIC MAINTENANCE AND MINOR REPAIR
6-33
6
EAUM1820
Replacing an auxiliary light
bulb If the auxiliary light bulb burns out, re-
place it as follows.
1. Remove cowling A together with
the headlight unit. (See page 6-5.)
2. Remove the auxiliary light socket
(together with the bulb) by pulling it
out.
3. Remove the defective bulb by pull-
ing it out.
4. Insert a new bulb into the socket.
5. Install the auxiliary light socket (to-
gether with the bulb) by pushing it
in.
6. Install the cowling together with
the headlight unit.
EAU24350
Supporting the motorcycle Since this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other maintenance
requiring the motorcycle to stand up-
right. Check that the motorcycle is in a
stable and level position before starting
any maintenance. A strong wooden
box can be placed under the engine for
added stability.
To service the front wheel
1. Stabilize the rear of the motorcycle
by using a motorcycle stand or, if
an additional motorcycle stand is
not available, by placing a jack un-
der the frame in front of the rear
wheel.
2. Raise the front wheel off the
ground by using a motorcycle
stand.
To service the rear wheel
Raise the rear wheel off the ground by
using a motorcycle stand or, if a motor-
cycle stand is not available, by placinga jack either under each side of the
frame in front of the rear wheel or under
each side of the swingarm.
1. Auxiliary light bulb socket
Page 72 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-34
6
EAU24360
Front wheel
EAUM1761
To remove the front 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. Loosen the front wheel axle pinch
bolts, then the wheel axle and the
brake caliper bolts.
XT660RXT660X
2. Lift the front wheel off the ground
according to the procedure on
page 6-33.
3. Remove the brake caliper by re-
moving the bolts.
CAUTION:
ECA11070
Do not apply the brake after the
wheel has been removed together
with the brake disc, otherwise thebrake pads will be forced shut.
4. Pull the wheel axle out, and then
remove the wheel.
EAUM1811
To install the front wheel
1. Lift the wheel up between the fork
legs.
2. Insert the wheel axle.
3. Lower the front wheel so that it is
on the ground.
1. Wheel axle
2. Front wheel axle pinch bolt A
3. Front wheel axle pinch bolt B
1. Wheel axle
2. Front wheel axle pinch bolt A
3. Front wheel axle pinch bolt B
1. Bolt
2. Brake caliper
Page 73 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-35
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
EAUM1771
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.
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
Page 74 of 90

PERIODIC MAINTENANCE AND MINOR REPAIR
6-36
63. Lift the rear wheel off the ground
according to the procedure on
page 6-33.
4. Loosen the locknut on each side of
the swingarm.
5. Turn the drive chain slack adjust-
ing nuts fully in direction (a).
6. Remove the wheel axle by remov-
ing the axle nut.
7. Push the wheel forward, and then
remove the drive chain from the
rear sprocket.
NOTE:The drive chain cannot be disassem-bled.
8. Pull the wheel backward and move
the brake caliper away from the
wheel.
CAUTION:
ECA11070
Do not apply the brake after the
wheel has been removed together
with the brake disc, otherwise thebrake pads will be forced shut.
EAUM1781
To install the rear wheel
1. Install the drive chain onto the rear
sprocket.
2. Install the wheel, the washers and
the brake caliper bracket by insert-
ing the wheel axle from the left-
hand side.
NOTE:
Install the washer with the “N”
mark on the right-hand side and
the washer with the “O” mark on
the left-hand side. Be sure to install
both washers with their marks fac-
ing outward.
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.
1. Brake caliper
2. Brake disc
1. Retainer
2. Slot