engine YAMAHA XT660Z 2015 Owner's Guide

PERIODIC MAINTENANCE AND ADJUSTMENT
6-9
6 To install the panel
Place the panel in the original position,
and then install the bolts.
EAU19605
Checking the spark plugThe 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 periodic main-
tenance and lubrication chart. In addi-
tion, the condition of the spark plug
can reveal the condition of the engine.
To remove the spark plug
1. Remove the spark plug cap.
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).
TIPIf the spark plug shows a distinctly dif-
ferent color, the engine could be oper-
ating improperly. Do not attempt to
diagnose such problems yourself. In-
stead, have a Yamaha dealer check
the vehicle.2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
necessary.
3. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifi-
cation.
1. Bolt
2. Panel B
1. Panel B
2. Center pin
2
ZAUM1240ZAUM1241
1. Spark plug cap
2. Spark plug wrench
Specified spark plug:
NGK/CR7E
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-10
6
To install the spark plug
1. Clean the surface of the spark
plug gasket and its mating sur-
face, and then wipe off any grime
from the spark plug threads.
2. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
TIPIf 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.3. Install the spark plug cap.
EAUB1567
Engine oil and oil filter ele-
mentThe engine oil level should be checked
before each ride. In addition, the oil
must be changed and the oil filter ele-
ment replaced at the intervals specified
in the periodic maintenance and lubri-
cation chart.
To check the engine oil level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.TIPMake 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. WARNING!
Never remove the engine oil fill-
er cap after high-speed opera-
1. Spark plug gapSpark plug gap:
0.7–0.8 mm (0.028–0.031 in)
Tightening torque:
Spark plug:
12.5 Nm (1.25 m·kgf, 9.04 ft·lbf)
1
ZAUM0037
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-11
6 tion, otherwise hot engine oil
could spout out and cause dam-
age or injury. Always let the en-
gine oil cool down sufficiently
before removing the oil filler
cap.
[EWA17640]
TIPThe engine oil tank is located in-
side of the frame.
The engine oil should be between
the minimum and maximum level
marks.4. If the engine oil is below the mini-
mum level mark, add sufficient oil
of the recommended type to raiseit to the correct level. NOTICE: Do
not operate the vehicle until you
know that the engine oil level is
sufficient.
[ECA10012]
5. Install the oil filler cap.
To change the engine oil (with or
without oil filter element replace-
ment)
1. Start the engine, warm it up for
several minutes, and then turn it
off.
2. Remove the engine guard by re-
moving 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 filler cap
2. Maximum level mark
3. Minimum level mark
1. Screw
2. Engine guard
1. Engine oil drain bolt (crankcase)
1. Engine oil drain bolt (oil tank)ZAUM1262ZAUM1263
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-12
66. Remove the oil filter element drain
bolt to drain the oil from the oil fil-
ter element.
TIPSkip steps 7…9 if the oil filter element is
not being replaced.7. Remove the oil filter element cover
by removing the bolts.
8. Remove and replace the oil filter
element and O-rings.TIPMake sure that the O-rings are properly
seated.
9. Install the oil filter element cover
by installing the bolts.
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.
12. Install the engine oil drain bolts,
and then tighten them to their
specified torques.13. Add the specified amount of the
recommended engine oil, and
then install and tighten the oil filler
cap.
NOTICE
ECAM1063
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 remain-
der of the engine oil.
1. Oil filter element drain bolt
2. Oil filter element cover bolt
1. Oil filter element
2. O-ringTightening 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
Engine oil drain bolt (oil tank):
18 Nm
Recommended engine oil:
See page 8-1.
Oil quantity:
Without oil filter element replace-
ment:
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)
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-13
6
TIPBe sure to wipe off spilled oil on any
parts after the engine and exhaust sys-
tem have cooled down.NOTICE
ECA11621
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 high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Make sure that no foreign mate-
rial 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 cause.
15. Turn the engine off, and then
check the oil level and correct it if
necessary.16. Install the engine guard by install-
ing the screws.
EAU20071
CoolantThe coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU20257
To check the coolant level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.TIP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.TIPThe coolant should be between the
minimum and maximum level marks.
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-14
6
3. If the coolant is at or below the
minimum level mark, remove pan-
el A (See page 6-8.), remove the
coolant 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 ra-
diator cap when the engine is
hot.
[EWA15162]
NOTICE: 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 cool-
ant as soon as possible, other-
wise 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.
[ECA10473]
EAU33032
Changing the coolant
The coolant must be changed at the in-
tervals specified in the periodic main-
tenance and lubrication chart. Have a
Yamaha dealer change the coolant.
WARNING! Never attempt to remove
the radiator cap when the engine is
hot.
[EWA10382]EAUB1483
Replacing the air filter ele-
ment and cleaning the check
hoseThe 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. Remove the seat. (See page 3-16.)
2. Remove the air filter case cover by
removing the screws.
1. Coolant reservoir
2. Maximum level mark
3. Minimum level mark
4. Coolant reservoir capZAUM1264
Coolant reservoir capacity (up to
the maximum level mark):
0.50 L (0.53 US qt, 0.44 Imp.qt)
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-15
6 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 seated
in the air filter case. The engine
should never be operated with-
out the air filter element in-
stalled, otherwise the piston(s)
and/or cylinder(s) may become
excessively worn.
[ECA10482]
5. Install the air filter case cover by
installing the screws.
6. Install the seat.
To clean the air filter check hose
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.
1. Air filter case cover
2. Screw
1. Air filter element

1. Air filter check hose
2. Air filter check hose plug
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-16
6
EAU21321
Adjusting the engine idling
speedThe engine idling speed must be
checked and, if necessary, adjusted as
follows at the intervals specified in the
periodic maintenance and lubrication
chart.
The engine should be warm before
making this adjustment.TIPThe engine is warm when it quickly re-
sponds to the throttle.Check the engine idling speed and, if
necessary, adjust it to specification by
turning the throttle stop screw. To in-
crease the engine idling speed, turn
the screw in direction (a). To decrease
the engine idling speed, turn the screw
in direction (b).
TIPIf the specified idling speed cannot be
obtained as described above, have a
Yamaha dealer make the adjustment.
EAU21385
Checking the throttle grip free
playThe throttle grip free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
inner edge of the throttle grip. Periodi-
cally check the throttle grip free play
and, if necessary, have a Yamaha deal-
er adjust it.
1. Idle adjusting screwEngine idling speed:
1400–1600 r/min
1. Throttle grip free play
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-17
6
EAU21402
Valve clearanceThe valve clearance changes with use,
resulting in improper air-fuel mixture
and/or engine noise. To prevent this
from occurring, the valve clearance
must be adjusted by a Yamaha dealer
at the intervals specified in the periodic
maintenance and lubrication chart.
EAU21647
TiresTires are the only contact between the
vehicle and the road. Safety in all con-
ditions of riding depends on a relatively
small area of road contact. Therefore, it
is essential to maintain the tires in good
condition at all times and replace them
at the appropriate time with the speci-
fied tires.
Tire air pressure
The tire air pressure should be
checked and, if necessary, adjusted
before each ride.
WARNING
EWA10504
Operation of this vehicle with im-
proper tire pressure may cause se-
vere injury or death from loss of
control.
The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).
The tire air pressure must be
adjusted in accordance with the
riding speed and with the totalweight of rider, passenger, car-
go, and accessories approved
for this model.
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-23
6
EAU22733
Changing the brake fluidHave a Yamaha dealer change the
brake fluid at the intervals specified in
the periodic maintenance and lubrica-
tion chart. In addition, have the oil seals
of the master cylinders and calipers as
well as the brake hoses replaced at the
intervals listed below or whenever they
are damaged or leaking.
Oil seals: Replace every two
years.
Brake hoses: Replace every four
years.
EAU22762
Drive chain slackThe drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22786
To check the drive chain slack
1. Place the motorcycle on the side-
stand.TIPWhen checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.2. Shift the transmission into the
neutral position.
3. Measure the drive chain slack as
shown.4. If the drive chain slack is incorrect,
adjust it as follows.
TIPWhen checking the drive chain slack,
the chain tensioner should not be
touching the drive chain.
EAU34318
To adjust the drive chain slack
Consult a Yamaha dealer before ad-
justing the drive chain slack.
1. Loosen the axle nut and the lock-
nut on each side of the swingarm.
2. To tighten the drive chain, turn the
drive chain slack adjusting bolt on
each side of the swingarm in di-
rection (a). To loosen the drive
chain, turn the adjusting bolt on
each side of the swingarm in di-
rection (b), and then push the rear
wheel forward. NOTICE: Improp-
er drive chain slack will over-
load the engine as well as other
vital parts of the motorcycle and
can lead to chain slippage or
breakage. To prevent this from
1. Drive chain slack
Drive chain slack:
50.0–60.0 mm (1.97–2.36 in)
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