2008 YAMAHA XT660Z check engine

PRE-OPERATION CHECKS
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ITEM
Fuel
Engine oil
Coolant
Front brake
Rear brake
EAU15605
Pre-operation check list
CHECKS
• Check fuel level in fuel tank.
• Refuel if necessary.
• Check fuel line for leakage.
• Check oil level in oil tank.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage.
• Check coolant level in reservoir.
• If necessary, add recommended coolant to specified level.
• Check cooling system for leakage.
• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add recommended brake fluid to specified level.
• Check hydraulic system for leakage.
• Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add recommended brake fluid to specified level.
• Check hydraulic system for leakage. PAGE
3-12
6-9
6-12
3-11, 6-21, 6-22, 6-26
3-11, 6-21, 6-22, 6-27

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OPERATION AND IMPORTANT RIDING POINTS
EAU15950
EWA10270
WARNING0
●Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer re-
garding any control or function
that you do not thoroughly un-
derstand.
●Never start the engine or oper-
ate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of con-
sciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.
●Before starting out, make sure
that the sidestand is up. If the
sidestand is not raised com-
pletely, it could contact the
ground and distract the opera-
tor, resulting in a possible loss
of control.

EAUB1570
Starting the engine
In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
●The transmission is in the neutral
position.
●The transmission is in gear with
the clutch lever pulled and the
sidestand up.
EWA10290
WARNING0
●Before starting the engine,
check the function of the igni-
tion circuit cut-off system ac-
cording to the procedure de-
scribed on page 3-18.
●Never ride with the sidestand
down.
1. Turn the key to “ON” and make sure that the engine stop switch is
set to “
I”.

ECAB0070CAUTION:
The following warning lights and in-
dicator lights should come on for a
few seconds, then go off.
●Neutral indicator light
●Turn signal indicator light
●High beam indicator light
●Engine trouble warning light
●Coolant temperature warning
light
●Immobilizer system indicator
light
If a warning or indicator light does
not go off, see page 3-3 for the cor-
responding warning and indicator
light circuit check.
2. Shift the transmission into the neutral position.
NOTE:
When the transmission is in the neu-
tral position, the neutral indicator light
should be on, otherwise have a Yama-
ha dealer check the electrical circuit.
5-1

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OPERATION AND IMPORTANT RIDING POINTS
ECA10310CAUTION:
●Keep the engine speed out of
the tachometer red zone.
●If any engine trouble should oc-
cur during the engine break-in
period, immediately have a
Yamaha dealer check the
vehicle.
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EAU17212
Parking
When parking, stop the engine, and
then remove the key from the main
switch.
EWA10310
WARNING0
●Since the engine and exhaust
system can become very hot,
park in a place where pedestri-
ans or children are not likely to
touch them.
●Do not park on a slope or on
soft ground, otherwise the ve-
hicle may overturn.
ECA10380CAUTION:
Never park in an area where there
are fire hazards such as grass or
other flammable materials.

XT660Z 04-06 ING 11-03-2008 8:30 Pagina 5-4

PERIODIC MAINTENANCE AND MINOR REPAIR
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• Check operation and for oil leakage.
• Check operation and shock absorber for oil
leakage.
• Check operation.
• Lubricate with lithium-soap-based grease.
• Adjust engine idling speed.
• Change.
• Check oil level and vehicle for oil leakage.
• Replace.
• Check coolant level and vehicle for coolant leakage.
• Change.
• Check operation.
• Lubricate.
• Check operation and free play.
• Adjust the throttle cable free play if necessary.
• Lubricate the throttle grip housing and cable.
Front fork
Shock absorber
assembly
Rear suspension
relay arm and
connecting arm
pivoting points
Fuel injection
Engine oil
Engine oil filter
element
Cooling system
Front and rear brake
switches
Moving parts and
cables
Throttle grip housing
and cable
√√√√
√√√√
√√√√
√√
√√√√√ √
√√√√√ √
√√√
√√√√ √
√√√√√ √ √√√√ √
√√√√ √18✻
19✻
20✻
21✻
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✻
25✻
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27
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NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (x 1,000 km)
110203040
ANNUAL
CHECK
Every 3 years

XT660Z 04-06 ING 11-03-2008 8:31 Pagina 6-4

PERIODIC MAINTENANCE AND MINOR REPAIR
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2. Remove the spark plug as shown, with the spark plug wrench includ-
ed in the owner’s tool kit.
To check the spark plug 1. Check that the porcelain insulator around the center electrode of the
spark plug is a medium-to-light
tan (the ideal color when the vehi-
cle is ridden normally).
NOTE:
If the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to di-
agnose such problems yourself.
Instead, have a Yamaha dealer check
the vehicle.
2. Check the spark plug for elec- trode erosion and excessive car-
bon or other deposits, and re-
place it if necessary.
Specified spark plug:CR7E (NGK)
Spark plug gap:0.7-0.8 mm (0.028-0.032 in)
To install the spark plug
1. Measure the spark plug gap with a wire thickness gauge and, if
necessary, adjust the gap to
specification.
1. Spark plug gap

2. Clean the surface of the sparkplug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
3. Install the spark plug with the spark plug wrench, and then tight-
en it to the specified torque.
EAU19603
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause
any spark plug to slowly erode, the
spark plug should be removed and
checked in accordance with the peri-
odic maintenance and lubrication
chart. In addition, the condition of the
spark plug can reveal the condition of
the engine.
To remove the spark plug
1. Spark plug cap
2. Spark plug wrench
1. Remove the spark plug cap.

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PERIODIC MAINTENANCE AND MINOR REPAIR
6-9
EAUB1560
Engine oil and oil filter
element
The engine oil level should be checked
before each ride. In addition, the oil must
be changed and the oil filter element re-
placed at the intervals specified in the
periodic maintenance and lubrication
chart.
To check the engine oil level1. Place the vehicle on a level surface and hold it in an upright position.
NOTE:
Make sure that the vehicle is posi-
tioned straight up when checking the
oil level. A slight tilt to the side can re-
sult in a false reading.
2. Start the engine, warm it up for 10-15 minutes and then turn it off.
3. Remove the oil filler cap, wipe the dipstick clean, insert it back into
the oil filler hole (without screwing
it in), and then remove it again to
check the oil level.
1. Engine oil filler cap
2. Maximum level mark
3. Minimum level mark
NOTE:
●The engine oil tank is located in-
side of the frame.
●The engine oil should be between
the minimum and maximum level
marks.

Tightening torque:Spark plug:12.5 Nm (1.25 m·kgf, 9.0 ft·lbf)
NOTE:
If a torque wrench is not available
when installing a spark plug, a good
estimate of the correct torque is 1/4-
1/2 turn past finger tight. However, the
spark plug should be tightened to the
specified torque as soon as possible.
4. Install the spark plug cap.

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PERIODIC MAINTENANCE AND MINOR REPAIR
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EAU20070
Coolant
The coolant level should be checked
before each ride. In addition, the
coolant must be changed at the inter-
vals specified in the periodic mainte-
nance and lubrication chart.
EAU20252
To check the coolant level 1. Place the vehicle on a level sur- face and hold it in an upright posi-
tion.
NOTE:
●The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
●Make sure that the vehicle is posi-
tioned 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.
ECA11620CAUTION:
● 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
higher quality than specified. In
addition, do not use oils la-
beled “ENERGY CONSERVING
II” or higher.
● Make sure that no foreign ma-
terial 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 en-
gine off and check for the cause.
15. Turn the engine off, and then check the oil level and correct it if
necessary.
16. Install the engine guard by in- stalling the screws.
NOTE:
Be sure to wipe off spilled oil on any
parts after the engine and exhaust
system have cooled down.
Recommended engine oil:See page 8-1.
Oil quantity: Without oil filter element
replacement:2.50 L (2.64 US qt) (2.19 Imp.qt)
With oil filter element replacement: 2.60 L (2.73 US qt) (2.26 Imp.qt)
ECAM1060CAUTION:
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.

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PERIODIC MAINTENANCE AND MINOR REPAIR
6-13
NOTE:
The coolant should be between the
minimum and maximum level marks.
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
4. Reservoir cap
3. If the coolant is at or below theminimum level mark, remove pan-
el E (See page 6-7.), remove the
reservoir cap, add coolant to the
maximum level mark, and then in-
stall the reservoir cap and the
panel.

ECA10471CAUTION:
● If coolant is not available, 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 antifreeze content of
the coolant as soon as possi-
ble, otherwise the effective-
ness of the coolant will be re-
duced.
Coolant reservoir capacity:
0.50 L (0.52 US qt) (0.44 Imp.qt)
EWA10380
WARNING0
Never attempt to remove the radia-
tor cap when the engine is hot.
NOTE:
●The radiator fan is automatically
switched on or off according to
the coolant temperature in the ra-
diator.
●If the engine overheats, see page
3-4 for further instructions.
EAU33030
Changing the coolant
EWA10380
WARNING0
Never attempt to remove the radia-
tor cap when the engine is hot.
The coolant must be changed at the
intervals specified in the periodic
maintenance and lubrication chart.
Have a Yamaha dealer change the
coolant.

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