Page 59 of 100

13. Add the specified amount of the
recommended engine oil, and
then install and tighten the oil
filler cap.
ECAM1061
The engine oil tank must be filled in
2 steps. First, fill the engine oil tank
with 1.90 L (2.0 US qt, 1.67 Imp.qt)
of the recommended engine oil.
Then, start the engine, race it 5 or 6
times, turn it off, and then add the
remainder of the engine oil.
TIP
Be sure to wipe off spilled oil on any
parts after the engine and exhaust
system have cooled down.
ECA11620
In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a hig-
her quality than specified. In
addition, do not use oils labe-
led “ENERGY CONSERVING II”
or higher.
Make sure that no foreign
material enters the crankcase.
14. Start the engine, and then let it
idle for several minutes while
checking it for oil leakage. If oil is
leaking, immediately turn the
engine off and check for the cau-
se.
15. Turn the engine off, and then
check the oil level and correct it if
necessary.16. Install the engine guard by insta-
lling the screws.
NOTICE
Recommended engine oil:
See page 8-1
Without oil filter element
replacement:
2.50 L (2.64 US qt, 2.20 Imp.qt)
With oil filter element
replacement:
2.60 L (2.75 US qt, 2.29 Imp.qt
NOTICE
Tightening torques:
Engine oil drain bolt (crankcase):
30 Nm (3.0 m·kgf, 22 ft·lbf)
Engine oil drain bolt (oil tank):
18 Nm (1.8 m·kgf, 12.9 ft·lbf)
PERIODIC MAINTENANCE AND ADJUSTMENT
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EAU20070
Coolant
The coolant level should be checked
before each ride. In addition, the coo-
lant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU20253
To check the coolant level
1. Place the vehicle on a level surface
and hold it in an upright position.
TIP
The coolant level must be chec-
ked on a cold engine since the
level varies with engine tempera-
ture.
Make sure that the vehicle is
positioned straight up when
checking the coolant level. A
slight tilt to the side can result in
a false reading.
2. Check the coolant level in the
coolant reservoir.
TIP
The coolant should be between the
minimum and maximum level marks.
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
4. Coolant reservoir cap
3. If the coolant is at or below the
minimum level mark, remove
panel E (See page 6-8). , remove
the reservoir cap, add coolant to
the maximum level mark, and
then install the reservoir cap and
the panel. WARNING! Remove
only the coolant reservoir cap.
Never attempt to remove the
radiator cap when the engine is
hot.
[EWA15161]
NOTICE: If coolant is not avai-
lable, use distilled water or soft
tap water instead. Do not use
hard water or salt water since it
is harmful to the engine. If
water has been used instead of
coolant, replace it with coolant
as soon as possible, otherwise
the cooling system will not be
protected against frost and
corrosion. If water has been
added to the coolant, have a
Yamaha dealer check the anti-
freeze content of the coolant
as soon as possible, otherwise
the effectiveness of the coolant
will be reduced.
[ECA10472]
Coolant reservoir capacity (up to
the maximum level mark):
0.50 L (0.53 US qt, 0.44 Imp.qt)
PERIODIC MAINTENANCE AND ADJUSTMENT
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EAU33031
Changing the coolant
The coolant must be changed at the
intervals specified in the periodic
maintenance and lubrication chart.
Have a Yamaha dealer change the
coolant. WARNING! Never attempt
to remove the radiator cap when
the engine is hot.
[EWA10381]EAUB1481
Replacing the air filter
element and cleaning the
check hose
The air filter element should be repla-
ced at the intervals specified in the
periodic maintenance and lubrication
chart. Replace the air filter element
more frequently if you are riding in
unusually wet or dusty areas. In addi-
tion, the air filter check hose must be
frequently checked and cleaned if
necessary.
To replace the air filter element
1. Remove the seat. (See page
3-16).
2. Remove the air filter case cover
by removing the screws.
1. Air filter case cover
2. Screw
3. Pull the air filter element out.
4. Insert a new air filter element into
the air filter case as shown.
NOTICE: Make sure that the air
filter element is properly sea-
ted in the air filter case. The
engine should never be opera-
ted without the air filter ele-
ment installed, otherwise the
piston(s) and/or cylinder(s)
may become excessively worn.
[ECA10481]
PERIODIC MAINTENANCE AND ADJUSTMENT
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Page 62 of 100
1. Air filter element
5. Install the air filter case cover by
installing the screws.
6. Install the seat.
To clean the air filter check hose
1. Air filter check hose
2. Check hose cap
1. Check the hose on the side of the
air filter case for accumulated dirt
or water.
2. If dirt or water is visible, remove
the hose, clean it, and then install
it.EAU44734
Checking the engine idling
speed
Check the engine idling speed and, if
necessary, have it corrected by a Yamaha
dealer.
Engine idling speed:
1400–1600 r/min
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EAU21383
Checking the throttle cable
free play
1. Throttle grip free play
The throttle cable free play should
measure 3.0–5.0 mm (0.12–0.20 in) at
the inner edge of the throttle grip.
Periodically check the throttle cable
free play and, if necessary, have a
Yamaha dealer adjust it.
EAU21401
Valve clearance
The valve clearance changes with
use, resulting in improper air-fuel mix-
ture and/or engine noise. To prevent
this from occurring, the valve clearan-
ce must be adjusted by a Yamaha
dealer at the intervals specified in the
periodic maintenance and lubrication
chart.
EAU21642
Tires
To maximize the performance, durabi-
lity, and safe operation of your
motorcycle, note the following points
regarding the specified tires.
Tire air pressure
The tire air pressure should be chec-
ked and, if necessary, adjusted befo-
re each ride.
EWA10503
Operation of this vehicle with
improper tire pressure may
cause severe injury or death
from loss of control.
The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperatu-
re of the tires equals the
ambient temperature).
The tire air pressure must be
adjusted in accordance with
the riding speed and with the
total weight of rider, passenger,
cargo, and accessories appro-
ved for this model.
WARNING
PERIODIC MAINTENANCE AND ADJUSTMENT
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Page 64 of 100

EWA10511
Never overload your vehicle. Ope-
ration of an overloaded vehicle
could cause an accident.
Tire inspection
1. Tire sidewall
2. Tire tread depth
The tires must be checked before each
ride. If the center tread depth reaches
the specified limit, if the tire has a nail or
glass fragments in it, or if the sidewall is
cracked, have a Yamaha dealer replace
the tire immediately.
TIPThe tire tread depth limits may differ
from country to country. Always comply
with the local regulations.
Tire information
This motorcycle is equipped with tube
tires.
EWA10461
The front and rear tires should be of
the same make and design, other-
wise the handling characteristics of
the vehicle may be different, which
could lead to an accident.
After extensive tests, only the tires lis-
ted below have been approved for
this model by Yamaha Motor Co., Ltd.
WARNING
Minimum tire tread depth (front
and rear):
1.6 mm (0.06 in)
WARNINGTire air pressure (measured on
cold tires):
0–90 kg (0–198 lb):
Front:
210 kPa (2.10 kgf/cm
2,
30 psi, 2.10 bar)
Rear:
230 kPa (2.30 kgf/cm
2,
33 psi, 2.30 bar)
XT660Z 90–190 kg (198–419 lb)
XT660ZA 90–188 kg (198–414 lb):
Front:
230 kPa (2.30 kgf/cm
2,
33 psi, 2.30 bar)
Rear:
250 kPa (2.50 kgf/cm
2,
36 psi, 2.50 bar)
Off-road riding:
Front:
200 kPa (2.00 kgf/cm
2,
29 psi, 2.00 bar)
Rear:
200 kPa (2.00 kgf/cm
2,
29 psi, 2.00 bar)
High-speed riding:
Front:
210 kPa (2.10 kgf/cm
2,
30 psi, 2.10 bar)
Rear:
230 kPa (2.30 kgf/cm
2,
33 psi, 2.30 bar)
Maximum load*:
XT660Z: 190 kg (419 lb)
XT660ZA: 188 kg (414 lb)
* Total weight of rider, passenger,
cargo and accessories
PERIODIC MAINTENANCE AND ADJUSTMENT
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-19
6
EWA10570
Have a Yamaha dealer replace
excessively worn tires. Besides
being illegal, operating the
motorcycle with excessively
worn tires decreases riding
stability and can lead to loss of
control.
The replacement of all wheel-
and brake-related parts, inclu-ding the tires, should be left to
a Yamaha dealer, who has the
necessary professional know-
ledge and experience.
It is not recommended to patch
a punctured tube. If unavoida-
ble, however, patch the tube
very carefully and replace it as
soon as possible with a high-
quality product.
EAU21942
Spoke wheelsEWA10610
The wheels on this model are not
designed for use with tubeless
tires. Do not attempt to use tube-
less tires on this model.
To maximize the performance, durabi-
lity, and safe operation of your
motorcycle, note the following points
regarding the specified wheels.
The wheel rims should be chec-
ked for cracks, bends or warpa-
ge, and the spokes for looseness
or damage before each ride. If
any damage is found, have a
Yamaha dealer replace the whe-
el. Do not attempt even the sma-
llest repair to the wheel. A defor-
med 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
handling characteristics, and a
shortened tire life.
WARNING
WARNING
Front tire:
Size:
XT660Z 90/90-21M/C 54S
XT660Z 90/90-21M/C 54T
XT660ZA 90/90-21M/C 54S
Manufacturer/model:
XT660Z METZELER/ TOURANCE
XT660Z MICHELIN/SIRAC
XT660ZA PIRELLI/SCORPION
TRAIL
Rear tire:
Size:
XT660Z 130/80-17M/C 65S
XT660Z 130/80-17M/C 65T
XT660ZA 130/80-17M/C 65S
Manufacturer/model:
XT660Z METZELER/ TOURANCE
XT660Z MICHELIN/SIRAC
XT660ZA PIRELLI/SCORPION
TRAIL
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EAU22043
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
lever free play and, if necessary,
adjust it as follows.
1. Slide the rubber cover back at
the clutch lever.
2. Loosen the locknut.
3. To increase the clutch lever free
play, turn the adjusting bolt in
direction (a). To decrease the
clutch lever free play, turn the
adjusting bolt in direction (b).
1. Locknut (clutch lever)
2. Clutch lever free play adjusting bolt
3. Clutch lever free play
TIP
If the specified clutch lever free play
could be obtained as described abo-
ve, skip steps 4–7.
4. Fully turn the adjusting bolt at the
clutch lever in direction (a) to loo-
sen the clutch cable.
5. Loosen the locknut at the crank-
case.
6. To increase the clutch lever free
play, turn the adjusting nut in
direction (a). To decrease the
clutch lever free play, turn the
adjusting nut in direction (b).
1. Locknut (crankcase)
2. Clutch lever free play adjusting nut (crank-
case)
7. Tighten the locknut at the crank-
case.
8. Tighten the locknut at the clutch
lever and then slide the rubber
cover to its original position.
PERIODIC MAINTENANCE AND ADJUSTMENT
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