Page 9 of 97

TABLE OF CONTENTS
Lubricating the rear suspension......6-27
Lubricating the swingarm pivots .....6-28
Checking the front fork ....................6-28
Checking the steering .....................6-29
Checking the wheel bearings..........6-29
Battery.............................................6-30
Replacing the fuses ........................6-31
Replacing a headlight bulb .............6-33
Tail/brake light .................................6-34
Replacing a turn signal light bulb....6-34
Replacing the license plate light bulb ...................................6-35
Replacing an auxiliary light bulb .....6-35
Supporting the motorcycle ..............6-36
Front wheel .....................................6-36
Rear wheel ......................................6-38
Troubleshooting ...............................6-39
Troubleshooting charts ....................6-40
MOTORCYCLE CARE
AND STORAGE ...................................7-1
Care ..................................................7-1
Storage..............................................7-3 SPECIFICATIONS
...............................8-1
CONSUMER INFORMATION ..............9-1
Identification numbers .......................9-1
XT660Z 01-03 ING 10-03-2008 16:11 Pagina 7
Page 15 of 97
10. Grab bar
11. Main fuse (page 6-31)
12. Battery (page 6-30)
13. Rear brake fluid reservoir (page 6-22)14. Coolant reservoir (page 6-12) 15. Front brake fluid reservoir (page 6-22)
16. Coolant drain bolt (page 6-12)
17. Engine oil filter element (page 6-10)
18. Brake pedal (page 3-11)
1
2
3
4
5
6
7
8
9
10
DESCRIPTION
EAU10420Right view
2-2
XT660Z 01-03 ING 10-03-2008 16:11 Pagina 13
Page 19 of 97

1
2
3
4
5
6
7
8
9
10
INSTRUMENT AND CONTROL FUNCTIONS
3-3
To unlock the steering
1. Push
2. Turn
Push the key in, and then turn it to
“OFF” while still pushing it.
EWA10060
WARNING0
Never turn the key to “OFF” or
“LOCK” while the vehicle is mov-
ing, otherwise the electrical sys-
tems will be switched off, which
may result in loss of control or an
accident. Make sure that the vehi-
cle is stopped before turning the
key to “OFF” or “LOCK”.
EAU10941
F(Parking)
The steering is locked, and the tail-
light, license plate light and auxiliary
lights are on. The hazard lights and
turn signal lights can be turned on, but
all other electrical systems are off. The
key can be removed.
The steering must be locked before
the key can be turned to “ F”.
ECA11020CAUTION:
Do not use the parking position for
an extended length of time, other-
wise the battery may discharge.
EAU11003
Indicator and warning lights
1. Immobilizer system indicator light “ ”
2. Neutral indicator light “ N”
3. Turn signal indicator light “ y”
4. High beam indicator light “ 1”
5. Engine trouble warning light “ U”
6. Coolant temperature warning light “ u”
EAUB1510
Turn signal indicator light “ y”
This indicator light flashes when the
turn signal switch is pushed to the left
or right.
The electrical circuit of the turn signal
indicator light can be checked by turn-
ing the key to "ON".
If the indicator light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical cir-
cuit.
XT660Z 01-03 ING 10-03-2008 16:11 Pagina 3-3
Page 26 of 97

INSTRUMENT AND CONTROL FUNCTIONS
3-10
1
2
3
4
5
6
7
8
9
10
EAU12733
Hazard switch “r”
With the key in the “ON” or Fposition,
use this switch to turn on the hazard
lights (simultaneous flashing of all turn
signal lights).
The hazard lights are used in case of
an emergency or to warn other drivers
when your vehicle is stopped where it
might be a traffic hazard.
ECA10061CAUTION:
Do not use the hazard lights for an
extended length of time with the
engine not running, otherwise the
battery may discharge.
EAU12820
Clutch lever
1. Clutch lever
The clutch lever is located at the left
handlebar grip. To disengage the
clutch, pull the lever toward the han-
dlebar grip. To engage the clutch, re-
lease the lever. The lever should be
pulled rapidly and released slowly for
smooth clutch operation.
The clutch lever is equipped with a
clutch switch, which is part of the igni-
tion circuit cut-off system. (See page
3-17).
1
EAU12870
Shift pedal
1. Shift pedal
The shift pedal is located on the left
side of the engine and is used in com-
bination with the clutch lever when
shifting the gears of the 5-speed con-
stant-mesh transmission equipped on
this motorcycle.
XT660Z 01-03 ING 10-03-2008 16:11 Pagina 3-10
Page 40 of 97

OPERATION AND IMPORTANT RIDING POINTS
3. Start the engine by pushing thestart switch.
NOTE:
If the engine fails to start, release the
start switch, wait a few seconds, and
then try again. Each starting attempt
should be as short as possible to pre-
serve the battery. Do not crank the en-
gine more than 10 seconds on any one
attempt.
ECA11040CAUTION:
For maximum engine life, never ac-
celerate hard when the engine is
cold!
NOTE:
The engine is warm when it quickly re-
sponds to the throttle.
EAU16671
Shifting
1. Shift pedal
N. Neutral position
Shifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing
hills, etc.
The gear positions are shown in the il-
lustration.
NOTE:
To shift the transmission into the neu-
tral position, press the shift pedal down
repeatedly until it reaches the end of its
travel, and then slightly raise it.
ECA10260CAUTION:
●Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long
distances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.
●Always use the clutch while
changing gears to avoid dam-
aging the engine, transmission,
and drive train, which are not
designed to withstand the
shock of forced shifting.
5-2
1
2
3
4
5
6
7
8
9
10
XT660Z 04-06 ING 11-03-2008 8:30 Pagina 5-2
Page 72 of 97

PERIODIC MAINTENANCE AND MINOR REPAIR
6-30
1
2
3
4
5
6
7
8
9
10
EWA10760
WARNING0
●Electrolyte is poisonous and
dangerous since it contains
sulfuric acid, which causes se-
vere burns. Avoid any contact
with skin, eyes or clothing and
always shield your eyes when
working 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 OF
CHILDREN.
EAUB1430
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.
ECA10620CAUTION:
Never attempt to remove the bat-
tery cell seals, as this would perma-
nently damage the battery.
To access the battery
Remove the battery holder bracket by
removing the bolts.
1. Positive battery terminal
2. Negative battery terminal
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.
XT660Z 04-06 ING 31-03-2008 14:05 Pagina 6-30
Page 73 of 97

1
2
3
4
5
6
7
8
9
10
PERIODIC MAINTENANCE AND MINOR REPAIR
6-31
To store the battery1. 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
connected to the battery termi-
nals.ECA10630CAUTION:
●Always keep the battery
charged. Storing a discharged
battery can cause permanent
battery damage.
●To charge a sealed-type (MF)
battery, a special (constant-
voltage) battery charger is re-
quired. Using a conventional
battery charger will damage
the battery. If you do not have
access to a sealed-type (MF)
battery charger, have a Yamaha
dealer charge your battery.
EAUB1490
Replacing the fuses
1. Main fuse
2. Reserve fuse
XT660Z 04-06 ING 31-03-2008 14:05 Pagina 6-31
Page 82 of 97

PERIODIC MAINTENANCE AND MINOR REPAIR
6-40
1
2
3
4
5
6
7
8
9
10
EAU42130Troubleshooting charts
Starting problems or poor engine performanceEWA10840
WARNING0
Keep away open flames and do not smoke while checking or working on the \
fuel system.
1. Fuel
2. Compression
3. Ignition
4. Battery
Check the fuel level in the
fuel tank.
Operate the electric
starter.
Remove the spark plug
and check the electrodes.
Operate the electric
starter.
There is enough
fuel.
There is
compression.
Wet.
The engine turns
over quickly.
There is no fuel.
There is no
compression.
Dry.
The engine turns
over slowly.
Check the
compression.
Check the ignition.
Wipe off with a dry cloth and correct
the spark plug gap, or replace the
spark plug.
The battery is good.
Have a Yamaha dealer check the
vehicle.
Check the battery lead connections,
and charge the battery if necessary.
Open the throttle halfway and
operate the electric starter.
The engine does not start.
Check the battery.
The engine does
not start. Have a
Yamaha dealer
check the vehicle.
Supply fuel.
Have a Yamaha dealer check
the vehicle.
The engine does not start.
Check the compression.
XT660Z 04-06 ING 11-03-2008 8:31 Pagina 6-40