
PERIODIC MAINTENANCE AND ADJUSTMENT
6-22
6Rear brake (for XT660Z)
Rear brake (for XT660ZA)
TIPThe rear brake fluid reservoir is located
under the seat. (See page 3-16.)
WARNING
EWA16011
Improper maintenance can result in
loss of braking ability. Observe
these precautions:
Insufficient brake fluid may al-
low air to enter the brake sys-
tem, reducing braking
performance.
Clean the filler cap before re-
moving. Use only DOT 4 brake
fluid from a sealed container.
Use only the specified brake flu-
id; otherwise, the rubber seals
may deteriorate, causing leak-
age.
Refill with the same type of
brake fluid. Adding a brake fluid
other than DOT 4 may result in a
harmful chemical reaction.
Be careful that water or dust
does not enter the brake fluid
reservoir when refilling. Water
will significantly lower the boil-
ing point of the fluid and may re-sult in vapor lock, and
dirt may
clog the ABS hydraulic unit
valves.
NOTICE
ECA17641
Brake fluid may damage painted
surfaces or plastic parts. Always
clean up spilled fluid immediately.As the brake pads wear, it is normal for
the brake fluid level to gradually go
down. A low brake fluid level may indi-
cate worn brake pads and/or brake
system leakage; therefore, be sure to
check the brake pads for wear and the
brake system for leakage. If the brake
fluid level goes down suddenly, have a
Yamaha dealer check the cause before
further riding.
1. Minimum level mark
1. Minimum level mark
Specified brake fluid:
DOT 4
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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)
U2BDE1E0.book Page 23 Tuesday, December 16, 2014 5:38 PM
![YAMAHA XT660Z 2015 Owners Manual PERIODIC MAINTENANCE AND ADJUSTMENT
6-24
6occurring, keep the drive chain
slack within the specified limits.
[ECA10572]
TIPUsing the alignment marks on each
side of the swingarm, make sure that
both d YAMAHA XT660Z 2015 Owners Manual PERIODIC MAINTENANCE AND ADJUSTMENT
6-24
6occurring, keep the drive chain
slack within the specified limits.
[ECA10572]
TIPUsing the alignment marks on each
side of the swingarm, make sure that
both d](/manual-img/51/53212/w960_53212-67.png)
PERIODIC MAINTENANCE AND ADJUSTMENT
6-24
6occurring, keep the drive chain
slack within the specified limits.
[ECA10572]
TIPUsing the alignment marks on each
side of the swingarm, make sure that
both drive chain pullers are in the same
position for proper wheel alignment.3. Tighten the axle nut, then the lock-
nuts to their specified torques.4. Make sure that the drive chain
pullers are in the same position,
the drive chain slack is correct,
and the drive chain moves
smoothly.
EAU23026
Cleaning and lubricating the
drive chainThe drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.NOTICE
ECA10584
The drive chain must be lubricated
after washing the motorcycle, riding
in the rain or riding in wet areas.1. Clean the drive chain with kero-
sene and a small soft brush.
NOTICE: To prevent damaging
the O-rings, do not clean the
drive chain with steam cleaners,
high-pressure washers or inap-
propriate solvents.
[ECA11122]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant. NOTICE: Do not use
engine oil or any other lubri-
cants for the drive chain, as they
1. Axle nut
2. Drive chain slack adjusting bolt
3. Locknut
4. Alignment marks
Tightening torques:
Axle nut:
104 Nm
Locknut:
16 Nm
U2BDE1E0.book Page 24 Tuesday, December 16, 2014 5:38 PM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-34
6
EAU42653
Replacing an auxiliary light
bulbThis model is equipped with two auxil-
iary lights. If an auxiliary light bulb
burns out, replace it as follows.
1. Remove panel B. (See page 6-8.)
2. Remove the auxiliary light socket
(together with the bulb) by pulling
it out.
3. Remove the burnt-out bulb by
pulling it out.
4. Insert a new bulb into the socket.
5. Install the auxiliary light socket (to-
gether with the bulb) by pushing it
in.
6. Install the panel.
EAU24182
Tail/brake lightThis model is equipped with an LED-
type tail/brake light.
If the tail/brake light does not come on,
have a Yamaha dealer check it.
EAU24205
Replacing a turn signal light
bulb1. Remove the turn signal light lens
by removing the screw.
2. Remove the burnt-out bulb by
pushing it in and turning it coun-
terclockwise.
3. Insert a new bulb into the socket,
push it in, and then turn it clock-
wise until it stops.
4. Install the lens by installing the
screw. NOTICE: Do not over-
tighten the screw, otherwise the
lens may break.
[ECA11192]
1. Auxiliary light bulb socket
2. Auxiliary light bulbZAUM1238
1. Screw
2. Turn signal light lens
3. Turn signal light bulb
1ZAUM1265
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PERIODIC MAINTENANCE AND ADJUSTMENT
6-37
6 7. Retighten pinch bolt A to the
specified torque.
8. Apply the brake lever several
times, and then while holding the
brake lever in, push down hard on
the handlebar several times to
check for proper fork operation.
EAU44802
Rear wheel (for non-ABS
models)
WARNING
EWA14841
For the ABS model, have a Yamaha
dealer remove and install the wheel.
EAU56711
To remove the rear wheel
WARNING
EWA10822
To avoid injury, securely support the
vehicle so there is no danger of it
falling over.1. Loosen the axle nut.2. Lift the rear wheel off the ground
according to the procedure on
page 6-35.
3. Remove the axle nut.
4. Fully loosen the locknut on each
side of the swingarm.
5. Turn the drive chain slack adjust-
ing bolts fully in direction (a) and
push the wheel forward.
Tightening torques:
Wheel axle:
59 Nm
Front wheel axle pinch bolt:
18 Nm
Brake caliper bolt:
40 Nm
1. Wheel axle nut
2. Drive chain slack adjusting bolt
3. Locknut
4. Drive chainZAUM1267
U2BDE1E0.book Page 37 Tuesday, December 16, 2014 5:38 PM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-38
6
6. Remove the drive chain from the
rear sprocket.
TIPIf the drive chain is difficult to re-
move, remove the wheel axle first,
and then lift the wheel upward
enough to remove the drive chain
from the rear sprocket.
The drive chain cannot be disas-
sembled.7. While supporting the brake caliper
bracket, pull the wheel axle out,
and then remove the wheel.
NOTICE: Do not apply the brakeafter the wheel and brake disc
have been removed, otherwise
the brake pads will be forced
shut.
[ECA11073]
To install the rear wheel
1. Install the wheel and the brake cal-
iper bracket by inserting the wheel
axle from the left-hand side.TIPMake sure that the slot in the
brake caliper bracket is fit over the
retainer on the swingarm.
Make sure that there is enough
space between the brake pads
before installing the wheel.2. Install the drive chain onto the rear
sprocket.
3. Install the axle nut, and then lower
the rear wheel so that it is on the
ground.
4. Adjust the drive chain slack. (See
page 6-23.)
5. Apply the rear brake several times,
and then tighten the axle nut to the
specified torque.
1. Wheel axle
2. Drive chain slack adjusting bolt
3. Locknut
4. Brake caliperZAUM1268
Tightening torque:
Axle nut:
104 Nm
U2BDE1E0.book Page 38 Tuesday, December 16, 2014 5:38 PM

PERIODIC MAINTENANCE AND ADJUSTMENT
6-41
6 Engine overheating
WARNING
EWAT1041
Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.
Place a thick rag, like a towel, over the radiator cap, and then slowly rotate the cap counterclockwise to the
detent to allow any residual pressure to escape. When the hissing sound has stopped, press down on the cap
while turning it counterclockwise, and then remove the cap.TIPIf coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended cool-
ant as soon as possible.
Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.Add coolant. (See TIP.)
Start the engine. If the engine overheats again,
have a
Yamaha dealer check
and repair the cooling system.
There is
leakage.
There is
no leakage.
U2BDE1E0.book Page 41 Tuesday, December 16, 2014 5:38 PM

10-1
10
INDEX
AABS (for ABS models) .......................... 3-12
ABS warning light (for ABS models) ....... 3-5
Air filter element and check hose,
replacing and cleaning ....................... 6-14
Auxiliary light bulb, replacing ............... 6-34BBattery .................................................. 6-29
Brake and clutch levers, checking and
lubricating........................................... 6-26
Brake fluid, changing............................ 6-23
Brake fluid level, checking.................... 6-21
Brake lever............................................ 3-11
Brake pedal .......................................... 3-11
Brake pedal, checking and
lubricating........................................... 6-26CCables, checking and lubricating ......... 6-25
Care ........................................................ 7-1
Catalytic converter ............................... 3-15
Clutch lever........................................... 3-10
Clutch lever free play, adjusting ........... 6-20
Coolant ................................................. 6-13
Coolant temperature warning light ......... 3-4DDimmer switch........................................ 3-9
Drive chain, cleaning and lubricating ... 6-24
Drive chain slack .................................. 6-23EEngine break-in ...................................... 5-3
Engine idling speed .............................. 6-16
Engine oil and oil filter element............. 6-10
Engine stop switch ............................... 3-10
Engine trouble warning light ................... 3-5
FFront and rear brake pads, checking ... 6-21
Front fork, adjusting ............................. 3-16
Front fork, checking ............................. 6-28
Fuel ...................................................... 3-13
Fuel consumption, tips for reducing ...... 5-3
Fuel tank breather/overflow hose ........ 3-15
Fuel tank cap........................................ 3-13
Fuses, replacing ................................... 6-31HHandlebar switches ............................... 3-9
Hazard switch ...................................... 3-10
Headlight bulb, replacing ..................... 6-32
High beam indicator light ....................... 3-4
Horn switch .......................................... 3-10IIdentification numbers ........................... 9-1
Ignition circuit cut-off system .............. 3-19
Immobilizer system ................................ 3-1
Immobilizer system indicator light ......... 3-5
Indicator lights and warning lights ......... 3-4LLicense plate light bulb, replacing ....... 6-35MMain switch/steering lock ...................... 3-2
Maintenance and lubrication, periodic... 6-4
Maintenance, emission control
system ................................................. 6-3
Matte color, caution ............................... 7-1
Model label............................................. 9-1
Multi-function display............................. 3-6NNeutral indicator light ............................. 3-4
PPanels, removing and installing .............. 6-8
Parking.................................................... 5-4
Part locations.......................................... 2-1
Pass switch............................................. 3-9RRear suspension, lubricating ................ 6-27SSafety information................................... 1-1
Seat....................................................... 3-16
Shifting.................................................... 5-2
Shift pedal............................................. 3-11
Shock absorber assembly, adjusting ... 3-18
Sidestand.............................................. 3-19
Sidestand, checking and lubricating .... 6-27
Spark plug, checking .............................. 6-9
Specifications ......................................... 8-1
Starting the engine ................................. 5-1
Start switch ........................................... 3-10
Steering, checking ................................ 6-28
Storage ................................................... 7-3
Supporting the motorcycle ................... 6-35
Swingarm pivots, lubricating ................ 6-27TTail/brake light ...................................... 6-34
Throttle grip and cable, checking and
lubricating ........................................... 6-25
Throttle grip free play, checking ........... 6-16
Tires ...................................................... 6-17
Tool kit .................................................... 6-2
Troubleshooting .................................... 6-39
Troubleshooting charts ......................... 6-40
Turn signal indicator light ....................... 3-4
Turn signal light bulb, replacing............ 6-34
U2BDE1E0.book Page 1 Tuesday, December 16, 2014 5:38 PM