2008 YAMAHA XT660Z Owners Manual

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PERIODIC MAINTENANCE AND MINOR REPAIR
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Panel E and F
1. Panel mounting bolt
2. Quick fastener
E. Right panel
F. Left panel
To remove one of the panels
1. Remove the bolts.
2. Remove the quick fastener and thenpull the panel off at the areas
shown.
T
o install the panel
1. Place the panel in the original posi- tion.
2. Install the quick fastener and the bolts.

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2E-F

Panel G
1. Panel mounting bolt
G. Panel
To remove the panel
Remove the bolts, and then pull the
panel off at the areas shown.

1. Panel
2. Pin
To install the panel
Place the panel in the original position,
and then install the bolts.

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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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To change the engine oil
(with or without oil filter element
replacement)
1. Mounting screw
2. Engine guard
1. Start the engine, warm it up for sev- eral minutes, and then turn it off.
2. To reach the drain bolt of the crankcase and the drain bolt of
the oil tank, remove the engine
guard by removing the screws.
3. Place an oil pan under the engine to collect the used oil.
4. Remove the engine oil filler cap and the drain bolt to drain the oil
from the crankcase.
5. Remove the drain bolt to drain the oil from the oil tank.

1. Engine oil crankcase drain bolt
1. Engine oil tank drain bolt
6. Remove the oil filter elementdrain bolt to drain the oil from the
oil filter element.

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ECA10010CAUTION:
Do not operate the vehicle until you
know that the engine oil level is suf-
ficient.
EWA10360
WARNING0
Never remove the engine oil tank
cap after high-speed operation,
otherwise hot engine oil could
spout out and cause damage or in-
jury. Always let the engine oil cool
down sufficiently before removing
the oil tank cap.
4. If the engine oil is below the mini- mum level mark, add sufficient oil
of the recommended type to raise
it to the correct level.
5. Install the oil filler cap.

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PERIODIC MAINTENANCE AND MINOR REPAIR
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Tightening torques:Oil filter element cover bolt:10 Nm (1.0 m·kgf, 7.2 ft·lbf)
Oil filter element drain bolt: 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
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)
13. Add the specified amount of the
recommended engine oil, and
then install and tighten the oil filter
cap.
10. Install the oil filter element drain
bolt.
11. Tighten the oil filter element cover bolts and the oil filter element
drain bolt to their specified
torques.1. Engine oil filter element
2. O-rings

12. Install the engine oil drain bolts,and then tighten them to their
specified torques.
NOTE:
Skip steps 7-9 if the oil filter element is
not being replaced.
7. Remove the oil filter element cov- er by removing the bolts.
8. Remove and replace the oil filter element and O-rings.
9. Install the oil filter element cover by installing the bolts.
NOTE:
Make sure that the O-rings are proper-
ly seated.
1. Engine oil filter element drain bolt
2. Oil filter element cover bolts

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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
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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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1. Air filter element
ECA10480CAUTION: ● Make sure that the air filter ele-
ment is properly seated in the
air filter case.
● The engine should never be op-
erated without the air filter ele-
ment installed, otherwise the
piston(s) and/or cylinder(s) may
become excessively worn.
5. Install the air filter case cover by installing the screws.
6. Install the seat.
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EAUB1480
Replacing the air filter
element and cleaning the
check hose
The air filter element should be re-
placed at the intervals specified in the
periodic maintenance and lubrication
chart. Replace the air filter element
more frequently if you are riding in un-
usually wet or dusty areas. In addition,
the air filter check hose must be fre-
quently checked and cleaned if neces-
sary. To replace the air filter element
1. Air filter case
2. Screws
1. Remove the seat. (See page 3-
14.)
2. Remove the air filter case cover by removing the screws.
3. Pull the air filter element out.
4. Insert a new air filter element into the air filter case as shown.
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