2015 YAMAHA XT660Z check engine

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.
U2BDE1E0.book Page 13 Tuesday, December 16, 2014 5:38 PM

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)
U2BDE1E0.book Page 14 Tuesday, December 16, 2014 5:38 PM

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
U2BDE1E0.book Page 15 Tuesday, December 16, 2014 5:38 PM

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
U2BDE1E0.book Page 16 Tuesday, December 16, 2014 5:38 PM

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.
U2BDE1E0.book Page 17 Tuesday, December 16, 2014 5:38 PM

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)
U2BDE1E0.book Page 23 Tuesday, December 16, 2014 5:38 PM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-35
6
EAUM2203
Replacing the license plate
light bulb1. Remove the socket (together with
the bulb) by pulling it out.
2. Remove the burnt-out bulb by
pulling it out.
3. Insert a new bulb into the socket.
4. Install the socket (together with
the bulb) by pushing it in.
EAU24351
Supporting the motorcycleSince this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other mainte-
nance requiring the motorcycle to
stand upright. Check that the motorcy-
cle is in a stable and level position be-
fore starting any maintenance. A
strong wooden box can be placed un-
der the engine for added stability.
To service the front wheel
1. Stabilize the rear of the motorcy-
cle by using a motorcycle stand
or, if an additional motorcycle
stand is not available, by placing a
jack under the frame in front of the
rear wheel.
2. Raise the front wheel off the
ground by using a motorcycle
stand.
To service the rear wheel
Raise the rear wheel off the ground by
using a motorcycle stand or, if a motor-
cycle stand is not available, by placinga jack either under each side of the
frame in front of the rear wheel or under
each side of the swingarm.
1. License plate light bulb socket
2. License plate light bulb
U2BDE1E0.book Page 35 Tuesday, December 16, 2014 5:38 PM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-40
6
EAU42706
Troubleshooting chartsStarting problems or poor engine performance
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the battery.
Supply fuel.
The engine does not start.
Check the battery.
Operate the electric starter.4. Compression
There is compression.
There is no compression.
The engine does not start.
Have a Yamaha dealer check the vehicle.Have a Yamaha dealer check the vehicle.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the vehicle.
The engine does not start.
Check the compression.
Operate the electric starter.2. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.
DryWet
Operate the electric starter.
Check the battery lead connections,
and have a Yamaha dealer charge
the battery if necessary.
The engine does not start.
Check the ignition.
U2BDE1E0.book Page 40 Tuesday, December 16, 2014 5:38 PM