2016 YAMAHA MT-125 maintenance

Periodic maintenance and adjustment
6-37
6
EAUM3510
Replacing the license plate
light bulb
1. Remove the license plate light unit
by removing the screw.
2. Remove the license plate light
bulb 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 socket (together with
the bulb) by pushing it in.
6. Install the license plate light unit by
installing the screw.
EAU24351
Supporting the motorcycle
Since 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 placing
a 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 unit
3. Screw
ZAUM1190
2
3
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Periodic maintenance and adjustment
6-38
6
EAU44792
Front wheel (for non-ABS
models)
WARNING
EWA14841
For the ABS model, have a Yamaha
dealer remove and install the wheel.
EAU56531
To remove the front wheel
WARNING
EWA10822
To avoid injury, securely support the
vehicle so there is no danger of it
falling over.
1. Loosen the front wheel axle pinch
bolts, then the wheel axle and the
brake caliper bolts.2. Lift the front wheel off the ground
according to the procedure in the
previous section “Supporting the
motorcycle”.
3. Remove the brake caliper by re-
moving the bolts. NOTICE: Do
not apply the brake after the
wheel and brake disc have been
removed, otherwise the brake
pads will be forced shut.
[ECA11073]
4. Pull the wheel axle out, and then
remove the wheel.
To install the front wheel
1. Lift the wheel up between the fork
legs.
2. Insert the wheel axle.
3. Lower the front wheel so that it is
on the ground.
4. Install the brake caliper by install-
ing the bolts.
TIP
Make sure that there is enough space
between the brake pads before install-
ing the brake caliper onto the brake
disc.
5. Tighten the wheel axle to the
specified torque.
1. Axle bolt
2. Front wheel axle pinch bolt A
3. Front wheel axle pinch bolt B
ZAUM12153
1. Brake caliper bolt
2. Brake caliper
ZAUM1192
UBR3E0E0.book Page 38 Friday, June 19, 2015 1:19 PM

Periodic maintenance and adjustment
6-39
6 6. Tighten the wheel axle pinch bolt
A and pinch bolt B to the specified
torques.
7. Retighten the wheel axle pinch
bolt A to the specified torque.
8. Tighten the brake caliper bolts to
the specified torques.
9. 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.
EAU56701
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 6-37.
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 (5.9 m·kgf, 43 ft·lbf)
Front wheel axle pinch bolt:
23 Nm (2.3 m·kgf, 17 ft·lbf)
Brake caliper bolt:
38 Nm (3.8 m·kgf, 27 ft·lbf)
1. Axle nut
2. Drive chain slack adjusting bolt
3. Locknut
4. Brake caliper
ZAUM1193
UBR3E0E0.book Page 39 Friday, June 19, 2015 1:19 PM

Periodic maintenance and adjustment
6-40
66. Remove the drive chain from the
rear sprocket.
TIP
If 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 brake
after 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.
TIP
Make 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.
4. Lower the rear wheel so that it is
on the ground, and then put the
sidestand down.
5. Adjust the drive chain slack. (See
page 6-24.)
6. Tighten the axle nut, and then
tighten the locknuts to the speci-
fied torques.
1. Drive chain slack adjusting bolt
2. Locknut
(a)
12
ZAUM11941. Retainer
2. Slot
Tightening torques:
Axle nut:
85 Nm (8.5 m·kgf, 61 ft·lbf)
Locknut:
16 Nm (1.6 m·kgf, 12 ft·lbf)
UBR3E0E0.book Page 40 Friday, June 19, 2015 1:19 PM

Periodic maintenance and adjustment
6-41
6
EAU25872
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur
during operation. Any problem in the
fuel, compression, or ignition systems,
for example, can cause poor starting
and loss of power.
The following troubleshooting charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your motorcycle
require any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the motorcycle
properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWA15142
When checking the fuel system, do
not smoke, and make sure there are
no open flames or sparks in the ar-
ea, including pilot lights from water
heaters or furnaces. Gasoline or
gasoline vapors can ignite or ex-
plode, causing severe injury or prop-
erty damage.
UBR3E0E0.book Page 41 Friday, June 19, 2015 1:19 PM

Periodic maintenance and adjustment
6-42
6
EAU68070
Troubleshooting charts
Starting problems or poor engine performance
1. FuelThere is enough fuel.
There is no fuel.Supply fuel.
The engine turns over
quickly.
Operate the electric
starter.
Check the
compression.
The engine turns over
slowly.
Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug.
Check the electrolyte
and battery lead
connections, and
charge the battery if
necessary.
The engine does not
start.
Have a Yamaha
dealer check the
vehicle.
4. BatteryThe battery is good.
3. IgnitionWet
Dry
The engine does not
start.
Check the
compression.
Have a Yamaha
dealer check the
vehicle.The engine does not
start.
Check the battery.
Remove the spark
plug and check
the electrodes.
Check the fuel level
in the fuel tank.
Operate the electric
starter.
Operate the electric
starter.
There is compression.
There is no
compression.Have a Yamaha dealer check the vehicle.
Check the ignition.2. Compression
UBR3E0E0.book Page 42 Friday, June 19, 2015 1:19 PM

Periodic maintenance and adjustment
6-43
6 Engine overheating
WARNING
EWA10401
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.
After removing the radiator cap retaining bolt, place a thick rag, like a
towel, over the radiator cap, and then slowly rotate the cap counter-
clockwise 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.
TIP
If coolant is not available, tap water can be temporarily used instead, provided
that it is changed to the recommended coolant as soon as possible.
Wait until the engine
has cooled.
Check the coolant
level in the reservoir
and radiator.Add coolant.
(See TIP.)
The coolant level is
OK.
There is no leakage.
There is leakage.
The coolant level is
low.
Check the cooling
system for leakage.
Have a Yamaha
dealer check and
repair the cooling
system.
Start the engine. If the engine overheats again,
have a Yamaha dealer check and repair the cooling
system.
UBR3E0E0.book Page 43 Friday, June 19, 2015 1:19 PM

10-1
10
Index
A
ABS (for ABS models) .......................... 3-15
ABS warning light (for ABS models)....... 3-2
Air filter element and check hose,
replacing and cleaning ....................... 6-14
Auxiliary lights ...................................... 6-35
B
Battery .................................................. 6-31
Brake and clutch levers, checking and
lubricating .......................................... 6-27
Brake fluid, changing ........................... 6-24
Brake fluid level, checking ................... 6-23
Brake lever ........................................... 3-14
Brake light switches ............................. 6-21
Brake pedal .......................................... 3-14
Brake pedal, checking and
lubricating .......................................... 6-28
Brake pedal free play, adjusting........... 6-21
C
Cables, checking and lubricating ......... 6-26
Care ........................................................ 7-1
Catalytic converter ............................... 3-18
Clutch lever .......................................... 3-13
Clutch lever free play, adjusting ........... 6-19
Coolant ................................................. 6-12
Cowlings, removing and installing ......... 6-7
D
Dimmer switch ..................................... 3-11
Drive chain, cleaning and lubricating ... 6-26
Drive chain slack .................................. 6-24
E
Engine break-in ...................................... 5-4
Engine idling speed, checking ............. 6-14
Engine oil and oil filter element .............. 6-9
Engine stop switch ............................... 3-12
Engine trouble warning light................... 3-2
F
Front and rear brake pads, checking ... 6-22
Front brake lever free play, checking ... 6-20
Front fork, checking ............................. 6-29
Fuel....................................................... 3-16
Fuel consumption, tips for reducing ...... 5-4
Fuel level warning light ........................... 3-2
Fuel tank cap........................................ 3-16
Fuses, replacing ................................... 6-32
H
Handlebar switches.............................. 3-11
Headlight bulb, replacing ..................... 6-34
High beam indicator light ....................... 3-2
Horn switch .......................................... 3-12
I
Identification numbers ............................ 9-1
Ignition circuit cut-off system ............... 3-20
Indicator lights and warning lights .......... 3-2
Info switch ............................................ 3-12
L
License plate light bulb, replacing ........ 6-37
M
Main switch/steering lock ....................... 3-1
Maintenance and lubrication, periodic ... 6-4
Maintenance, emission control
system .................................................. 6-3
Matte color, caution ................................ 7-1
Model label ............................................. 9-1
Multi-function meter unit ........................ 3-4
N
Neutral indicator light.............................. 3-2
P
Parking .................................................... 5-5
Part locations .......................................... 2-1
Pass switch........................................... 3-11
R
Rider seat.............................................. 3-18
S
Safety information................................... 1-1
Shifting .................................................... 5-3
Shift pedal............................................. 3-13
Sidestand .............................................. 3-19
Sidestand, checking and lubricating .... 6-28
Spark plug, checking .............................. 6-8
Specifications ......................................... 8-1
Starting the engine.................................. 5-2
Start switch ........................................... 3-12
Steering, checking ................................ 6-30
Storage ................................................... 7-4
Supporting the motorcycle ................... 6-37
Swingarm pivots, lubricating ................ 6-29
T
Tail/brake light ...................................... 6-36
Throttle grip and cable, checking and
lubricating ........................................... 6-27
Throttle grip free play, adjusting ........... 6-15
Tires ...................................................... 6-16
Tool kit .................................................... 6-2
Troubleshooting .................................... 6-41
Troubleshooting charts ......................... 6-42
Turn signal indicator light ....................... 3-2
Turn signal light bulb, replacing............ 6-36
Turn signal switch ................................. 3-12
UBR3E0E0.book Page 1 Friday, June 19, 2015 1:19 PM