2008 YAMAHA XT660Z check engine

TABLE OF CONTENTS
SAFETY INFORMATION.....................1-1
Safe riding .........................................1-1
Protective apparel .............................1-2
Modifications .....................................1-2
Loading and accessories ..................1-2
Gasoline and exhaust gas ................1-4
DESCRIPTION .....................................2-1
Left view ............................................2-1
Right view .........................................2-2
Controls and instruments ..................2-3
INSTRUMENT AND CONTROL
FUNCTIONS ........................................3-1
Immobilizer system ...........................3-1
Main switch/steering lock ..................3-2
Indicator and warning lights ..............3-3
Multi-function display ........................3-5
Tachometer .......................................3-6
Tripmeter and tachometer modes .....3-6
Clock mode .......................................3-7
Fuel meter .........................................3-7
Self-diagnosis devices ......................3-7
Anti-theft alarm (optional) .................3-8
Handlebar switches ...........................3-9
Clutch lever .....................................3-10
Shift pedal .......................................3-10
Brake lever ......................................3-11
Brake pedal .....................................3-11 Fuel tank cap ..................................3-11
Fuel .................................................3-12
Fuel tank breather hose ..................3-13
Catalytic converter ..........................3-13
Seat .................................................3-14
Adjusting the front fork ....................3-15
Adjusting the shock absorber
assembly ..................................3-16
Sidestand ........................................3-17
Ignition circuit cut-off system ..........3-17
PRE-OPERATION CHECKS ...............4-1
Pre-operation check list ....................4-2
OPERATION AND IMPORTANT
RIDING POINTS ..................................5-1
Starting the engine............................5-1
Shifting ..............................................5-2
Tips for reducing fuel consumption ...5-3
Engine break-in .................................5-3
Parking ..............................................5-4
PERIODIC MAINTENANCE
AND MINOR REPAIR .........................6-1
Owner’s tool kit .................................6-1
Periodic maintenance and lubrication chart..........................6-2
Removing and installing the cowling and panels..................................6-8 Checking the spark plug ...................6-8
Engine oil and oil filter element.........6-9
Coolant ............................................6-12
Replacing the air filter element
and cleaning the check hose ..... 6-14
Checking the engine idling speed ...6-15
Checking the throttle cable free play ...................................6-16
Valve clearance ...............................6-16
Tires ................................................6-16
Spoke wheels..................................6-19
Adjusting the clutch lever free play ...................................6-20
Checking the front and rear brake pads ...............................6-21
Checking the brake fluid level .........6-22
Changing the brake fluid .................6-23
Drive chain slack .............................6-23
Cleaning and lubricating the drive chain ................................6-25
Checking and lubricating the cables .......................................6-25
Checking and lubricating the throttle grip and cable ..............6-26
Checking and lubricating the brake and clutch levers ............6-26
Lubricating the brake pedal ............6-27
Checking and lubricating the sidestand ..................................6-27

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INSTRUMENT AND CONTROL FUNCTIONS
3-3
To unlock the steering
1. Push
2. Turn
Push the key in, and then turn it to
“OFF” while still pushing it.
EWA10060
WARNING0
Never turn the key to “OFF” or
“LOCK” while the vehicle is mov-
ing, otherwise the electrical sys-
tems will be switched off, which
may result in loss of control or an
accident. Make sure that the vehi-
cle is stopped before turning the
key to “OFF” or “LOCK”.

EAU10941
F(Parking)
The steering is locked, and the tail-
light, license plate light and auxiliary
lights are on. The hazard lights and
turn signal lights can be turned on, but
all other electrical systems are off. The
key can be removed.
The steering must be locked before
the key can be turned to “ F”.
ECA11020CAUTION:
Do not use the parking position for
an extended length of time, other-
wise the battery may discharge.
EAU11003
Indicator and warning lights
1. Immobilizer system indicator light “ ”
2. Neutral indicator light “ N”
3. Turn signal indicator light “ y”
4. High beam indicator light “ 1”
5. Engine trouble warning light “ U”
6. Coolant temperature warning light “ u”
EAUB1510
Turn signal indicator light “ y”
This indicator light flashes when the
turn signal switch is pushed to the left
or right.
The electrical circuit of the turn signal
indicator light can be checked by turn-
ing the key to "ON".
If the indicator light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical cir-
cuit.

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INSTRUMENT AND CONTROL FUNCTIONS
3-4
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EAUB1520
Neutral indicator light “ N”
This indicator light comes on when the
transmission is in the neutral position.
The electrical circuit of the neutral indi-
cator light can be checked by turning
the key to "ON".
If the indicator light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical cir-
cuit.
EAUB1530
High beam indicator light “ 1”
This indicator light comes on when the
high beam of the headlight is switched
on. The electrical circuit of the high
beam indicator light can be checked
by turning the key to "ON".
If the indicator light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical cir-
cuit.
EAU11440
Coolant temperature warning
light “u ”
This warning light comes on when the
engine overheats. When this occurs,
stop the engine immediately and allow
the engine to cool. The electrical circuit of the warning
light can be checked by turning the
key to “ON”.
If the warning light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical cir-
cuit.
ECA10020
CAUTION:
Do not operate the engine if it is
overheated.
EAU11530
Engine trouble warning light “ U”
This warning light comes on or flashes
when an electrical circuit monitoring
the engine is defective. When this oc-
curs, have a Yamaha dealer check the
self-diagnosis system. (See page 3-7
for an explanation of the self-diagnosis
device.)
The electrical circuit of the warning
light can be checked by turning the
key to “ON”. If the warning light does
not come on for a few seconds, then
go off, have a Yamaha dealer check
the electrical circuit.
EAU26873
Immobilizer system indicator
light “ ”
The electrical circuit of the indicator
light can be checked by turning the
key to “ON”.
If the inidcator light does not come on
for a few seconds, then go off, have a
Yamaha dealer check the electrical cir-
cuit.
When the key is turned to “OFF” and
30 seconds have passed, the indicator
light will start flashing indicating the
immobilizer system is enabled. After
24 hours have passed, the indicator
light will stop flashing, however the im-
mobilizer system is still enabled.
This model is also equipped with a
self-diagnosis device for the immobi-
lizer system. (See page 3-7 for an ex-
planation of the self-diagnosis device.)

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INSTRUMENT AND CONTROL FUNCTIONS
3-7
Clock mode
1. Clock
2. “SELECT” button
3. “RESET” button
NOTE:
The clock is displayed even when the
key is turned to "OFF".
T
o set the clock:
1. Push the "SELECT" button for atleast four seconds.
2. When the hour digits start flash- ing, push the "RESET" button to
set the hours.
3. Push the "SELECT" button, and the minute digits will start flashing.
4. Push the "RESET" button to set the minutes.
5. Push the "SELECT" button and then release it to start the clock.
Fuel meter
1. Fuel meter
With the key in the "ON" position, the
fuel meter indicates the amount of fuel
in the fuel tank. When the key is turned
to "ON", all of the display segments of
the fuel meter will appear one after the
other and then disappear in order to
test the electrical circuit. The display
segments of the fuel meter disappear
towards "E" (Empty) as the fuel level
decreases. When only one segment is
left near "E" (Empty), refuel as soon
as possible.
NOTE:
This fuel meter is equipped with a self-
diagnosis system. If the electrical circuit
is defective, all the segments will start
flashing. If this occurs, have a Yamaha
dealer check the electrical circuit.
Self-diagnosis devices
1. Engine trouble warning light “ U”
2. Immobilizer system indicator light “ ”
This model is equipped with a self-di-
agnosis device for various electrical
circuits.
If any of those circuits are defective,
the engine trouble warning light will
start flashing. If this occurs, have a
Yamaha dealer check the vehicle.
This model is also equipped with a
self-diagnosis device for the immobi-
lizer system.
If any of the immobilizer system cir-
cuits are defective, the immobilizer
system indicator light will start flash-
ing.
If this occurs, have a Yamaha dealer
check the vehicle.
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INSTRUMENT AND CONTROL FUNCTIONS
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NOTE:
If the indicator light slowly flashes five
times, and then quickly flashes two
times repeatedly, this error could be
caused by transponder interference. If
this occurs, try the following. 1. Use the code re-registering key to start the engine.
NOTE:
Make sure there are no other immobi-
lizer keys close to the main switch, and
do not keep more than one immobiliz-
er key on the same key ring! Immobi-
lizer system keys may cause signal in-
terference, which may prevent the
engine from starting.
2. If the engine starts, turn it off, and try starting the engine with the
standard keys.
3. If one or both of the standard keys do not start the engine, take the
vehicle, the code re-registering
key and both standard keys to a
Yamaha dealer and have the
standard keys re-registered. If the immobilizer system indicator
light continues to flash, have a Yama-
ha dealer check the vehicle.
EAU12331
Anti-theft alarm (optional)
This motorcycle can be equipped with
an optional anti-theft alarm by a Yama-
ha dealer. Contact a Yamaha dealer for
more information.
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INSTRUMENT AND CONTROL FUNCTIONS
3-13
EAU13412
Fuel tank breather hose
1. Fuel tank breather hose
2. Clamp
Before operating the motorcycle:
●Check the fuel tank breather hose
connection.
●Check the fuel tank breather hose
for cracks or damage, and replace
it if damaged.
●Make sure that the fuel tank
breather hose is not blocked, and
clean it if necessary.

ECA11400CAUTION:
Use only unleaded gasoline. The
use of leaded gasoline will cause
severe damage to internal engine
parts, such as the valves and piston
rings, as well as to the exhaust sys-
tem.
Your Yamaha engine has been de-
signed to use premium unleaded
gasoline with a research octane num-
ber of 95 or higher. If knocking (or
pinging) occurs, use a gasoline of a
different brand. Use of unleaded fuel
will extend spark plug life and reduce
maintenance costs.
EAU13431
Catalytic converter
This model is equipped with a catalyt-
ic converter in the exhaust system.
EWA10860
WARNING0
The exhaust system is hot after op-
eration. Make sure that the exhaust
system has cooled down before
doing any maintenance work.

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EWA10240
WARNING0
The vehicle must not be ridden
with the sidestand down, or if the
sidestand cannot be properly
moved up (or does not stay up),
otherwise the sidestand could con-
tact the ground and distract the
operator, resulting in a possible
loss of control. Yamaha’s ignition
circuit cut-off system has been de-
signed to assist the operator in ful-
filling the responsibility of raising
the sidestand before starting off.
Therefore, check this system regu-
larly as described below and have
a Yamaha dealer repair it if it does
not function properly.

EAU15301
Sidestand
1. Sidestand
The sidestand is located on the left
side of the frame. Raise the sidestand
or lower it with your foot while holding
the motorcycle upright.
NOTE:
The built-in sidestand switch is part of
the ignition circuit cut-off system,
which cuts the ignition in certain situa-
tions. (See further down for an expla-
nation of the ignition circuit cut-off sys-
tem.)

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INSTRUMENT AND CONTROL FUNCTIONS
3-17
EAU15312
Ignition circuit cut-off
system
The ignition circuit cut-off system
(comprising the sidestand switch,
clutch switch and neutral switch) has
the following functions.
●It prevents starting when the
transmission is in gear and the
sidestand is up, but the clutch
lever is not pulled.
●It prevents starting when the
transmission is in gear and the
clutch lever is pulled, but the side-
stand is still down.
●It cuts the running engine when
the transmission is in gear and
the sidestand is moved down.
Periodically check the operation of the
ignition circuit cut-off system accord-
ing to the following procedure.
EWA10250
WARNING0
If a malfunction is noted, have a
Yamaha dealer check the system
before riding.

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INSTRUMENT AND CONTROL FUNCTIONS
3-18
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With the engine turned off:
1. Move the sidestand down.
2. Make sure that the engine stop switch is turned on.
3. Turn the key on.
4. Shift the transmission into the neutral position.
5. Push the start switch.
Does the engine start?
With the engine still running:
6. Move the sidestand up.
7. Keep the clutch lever pulled.
8. Shift the transmission into gear.
9. Move the sidestand down.
Does the engine stall?
NOTE:
This check is most reliable if performed with a
warmed-up engine.
The neutral switch may be defective.
The motorcycle should not be ridden until checked by a
Yamaha dealer.
The sidestand switch may be defective.
The motorcycle should not be ridden until checked by a
Yamaha dealer.
The clutch switch may be defective.
The motorcycle should not be ridden until checked by a
Yamaha dealer.
After the engine has stalled:
10. Move the sidestand up.
11. Keep the clutch lever pulled.
12. Push the start switch.
Does the engine start?
The system is OK. The motorcycle can be ridden.
YES NO
NO
YES
NO
YES

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