2017 YAMAHA MT-125 ignition

Table of contents
Safety information............................1-1
Description........................................2-1
Left view ..........................................2-1
Right view........................................2-2
Controls and instruments ................2-3
Instrument and control functions....3-1
Main switch/steering lock ...............3-1
Indicator lights and warning
lights ............................................3-2
Multi-function meter unit .................3-4
Handlebar switches.......................3-12
Clutch lever ...................................3-13
Shift pedal .....................................3-14
Brake lever ....................................3-14
Brake pedal ...................................3-15
ABS ...............................................3-15
Fuel tank cap.................................3-16
Fuel................................................3-17
Catalytic converter ........................3-18
Rider seat ......................................3-19
Sidestand ......................................3-20
Ignition circuit cut-off system........3-20
For your safety – pre-operation
checks...............................................4-1
Operation and important riding
points.................................................5-1
Starting the engine ..........................5-2
Shifting ............................................5-3
Tips for reducing fuel
consumption ................................5-4
Engine break-in ...............................5-4
Parking ............................................5-5
Periodic maintenance and
adjustment........................................6-1
Owner’s tool kit ...............................6-2
Periodic maintenance chart for the
emission control system ..............6-3
General maintenance and
lubrication chart ...........................6-4
Removing and installing cowlings ...6-7
Checking the spark plug .................6-8Engine 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......................................... 6-14
Adjusting the throttle grip free
play ............................................ 6-15
Valve clearance ............................. 6-16
Tires .............................................. 6-16
Cast wheels .................................. 6-19
Adjusting the clutch lever free
play ............................................ 6-19
Checking the front brake lever
free play ..................................... 6-20
Adjusting the brake pedal free
play ............................................ 6-21
Brake light switches ...................... 6-21
Checking the front and rear brake
pads........................................... 6-22
Checking the brake fluid level....... 6-23
Changing the brake fluid............... 6-24
Drive chain slack ........................... 6-24
Cleaning and lubricating the drive
chain .......................................... 6-26
Checking and lubricating the
cables ........................................ 6-26
Checking and lubricating the
throttle grip and cable ............... 6-27
Checking and lubricating the
brake and clutch levers ............. 6-27
Checking and lubricating the
brake pedal................................ 6-28
Checking and lubricating the
sidestand ................................... 6-28
Lubricating the swingarm
pivots ......................................... 6-29
Checking the front fork ................. 6-29
Checking the steering ................... 6-30
Checking the wheel bearings ....... 6-30
Battery .......................................... 6-31
Replacing the fuses ...................... 6-32
Replacing the headlight bulb ........ 6-33
Auxiliary lights ............................... 6-35
Tail/brake light .............................. 6-35
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Instrument and control functions
3-1
3
EAU10462
Main switch/steering lock
The main switch/steering lock controls
the ignition and lighting systems, and is
used to lock the steering. The various
positions are described below.
EAU36871ON
All electrical circuits are supplied with
power, the meter lighting, taillight, li-
cense plate light and auxiliary lights
come on, and the engine can be start-
ed. The key cannot be removed.
TIP
The headlight comes on automatically
when the engine is started and stays

even if the engine stalls.
EAU10662OFF
All electrical systems are off. The key
can be removed.
WARNING
EWA10062
Never turn the key to “OFF” or
“LOCK” while the vehicle is moving.
Otherwise the electrical systems will
be switched off, which may result in
loss of control or an accident.
EAU10696LOCK
The steering is locked and all electrical
systems are off. The key can be re-
moved.
To lock the steering
1. Turn the handlebars all the way to
the left or right.
2. With the key in the “OFF” position,
push the key in and turn it to
“LOCK”.
3. Remove the key.
TIP
If the steering will not lock, try turning
the handlebars back to the right or left
slightly.
To unlock the steering
1. Push.
2. Turn.
1. Push.
2. Turn.
12
12
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Instrument and control functions
3-17
3
EAU13213
Fuel
Make sure there is sufficient gasoline in
the tank.
WARNING
EWA10882
Gasoline and gasoline vapors are
extremely flammable. To avoid fires
and explosions and to reduce the
risk of injury when refueling, follow
these instructions.
1. Before refueling, turn off the en-
gine and be sure that no one is sit-
ting on the vehicle. Never refuel
while smoking, or while in the vi-
cinity of sparks, open flames, or
other sources of ignition such as
the pilot lights of water heaters
and clothes dryers.
2. Do not overfill the fuel tank. Stop
filling when the fuel reaches the
bottom of the filler tube. Because
fuel expands when it heats up,
heat from the engine or the sun
can cause fuel to spill out of the
fuel tank.
3. Wipe up any spilled fuel immedi-
ately. NOTICE: Immediately
wipe off spilled fuel with a clean,dry, soft cloth, since fuel may
deteriorate painted surfaces or
plastic parts.
[ECA10072]
4. Be sure to securely close the fuel
tank cap.
WARNING
EWA15152
Gasoline is poisonous and can
cause injury or death. Handle gaso-
line with care. Never siphon gasoline
by mouth. If you should swallow
some gasoline or inhale a lot of gas-
oline vapor, or get some gasoline in
your eyes, see your doctor immedi-
ately. If gasoline spills on your skin,
wash with soap and water. If gaso-
line spills on your clothing, change
your clothes.
EAU75320
NOTICE
ECA11401
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 system.
1. Fuel tank filler tube
2. Maximum fuel level
Recommended fuel:
Premium unleaded gasoline (Gaso-
hol [E10] acceptable)
Fuel tank capacity:
11.5 L (3.04 US gal, 2.53 Imp.gal)
Fuel reserve amount (when the fuel
level warning light comes on):
3.0 L (0.79 US gal, 0.66 Imp.gal)
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Instrument and control functions
3-20
3
EAU15306
Sidestand
The sidestand is located on the left
side of the frame. Raise the sidestand
or lower it with your foot while holding
the vehicle upright.
TIP
The built-in sidestand switch is part of
the ignition circuit cut-off system,
which cuts the ignition in certain situa-
tions. (See the following section for an
explanation of the ignition circuit cut-
off system.)
WARNING
EWA10242
The vehicle must not be ridden with
the sidestand down, or if the side-
stand cannot be properly moved up
(or does not stay up), otherwise the
sidestand could contact the ground
and distract the operator, resulting
in a possible loss of control.
Yamaha’s ignition circuit cut-off
system has been designed to assist
the operator in fulfilling the respon-
sibility of raising the sidestand be-
fore starting off. Therefore, check
this system regularly and have a
Yamaha dealer repair it if it does not
function properly.
EAU66730
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 le-
ver 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.
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For your safety – pre-operation checks
4-2
4
Control cables• Make sure that operation is smooth.
• Lubricate if necessary.6-26
Drive chain• Check chain slack.
• Adjust if necessary.
• Check chain condition.
• Lubricate if necessary.6-24,
6-26
Wheels and tires•Check for damage.
• Check tire condition and tread depth.
• Check air pressure.
• Correct if necessary.6-16,
6-19
Brake pedal• Make sure that operation is smooth.
• Lubricate pedal pivoting point if necessary.6-28
Brake and clutch le-
vers• Make sure that operation is smooth.
• Lubricate lever pivoting points if necessary.6-27
Sidestand• Make sure that operation is smooth.
• Lubricate pivot if necessary.6-28
Chassis fasteners• Make sure that all nuts, bolts and screws are properly
tightened.
• Tighten if necessary.—
Instruments, lights,
signals and switches• Check operation.
• Correct if necessary.—
Sidestand switch • Check operation of ignition circuit cut-off system.
• If system is not working correctly, have Yamaha dealer
check vehicle.3-20
Battery• Check fluid level.
• Fill with distilled water if necessary.6-31 ITEM CHECKS PAGE
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Operation and important riding points
5-2
5
EAUM3531
Starting the engine
In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
The transmission is in the neutral
position.
The transmission is in gear with
the clutch lever pulled and the
sidestand up.
See page 3-20 for more informa-
tion.
1. Turn the key to “ON” and make
sure that the engine stop switch is
set to “ ”.
The following warning lights and
indicator lights should come on for
a few seconds, then go off.
Neutral indicator light
Turn signal indicator light
High beam indicator light
Engine trouble warning light
Fuel level warning light
Tachometer high-rpm warn-
ing light
NOTICE
ECA11834
If a warning or indicator light does
not come on initially when the key is
turned to “ON”, or if a warning or in-
dicator light remains on, see page
3-2 for the corresponding warning
and indicator light circuit check.
The ABS warning light should
come on when the key is turned to
“ON”, and then go off after travel-
ing at a speed of 10 km/h (6 mi/h)
or higher.
NOTICE
ECA17682
If the ABS warning light does not
come on and then go off as ex-
plained above, see page 3-2 for the
warning light circuit check.
2. Shift the transmission into the
neutral position. The neutral indi-
cator light should come on. If not,
ask a Yamaha dealer to check the
electrical circuit.
3. Start the engine by pushing the
start switch.
If the engine fails to start, release
the start switch, wait a few sec-
onds, and then try again. Each
starting attempt should be as
short as possible to preserve the
battery. Do not crank the engine
more than 10 seconds on any one
attempt.
NOTICE
ECA11043
For maximum engine life, never ac-
celerate hard when the engine is
cold!
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Periodic maintenance and adjustment
6-33
6
3. Turn the key to “ON” and turn on
the electrical circuit in question to
check if the device operates.
4. If the fuse immediately blows
again, have a Yamaha dealer
check the electrical system.
EAUM3501
Replacing the headlight bulb
This model is equipped with a halogen
bulb headlight. If the headlight bulb
burns out, replace it as follows.
NOTICE
ECA10651
Take care not to damage the follow-
ing parts:
Headlight bulb
Do not touch the glass part of
the headlight bulb to keep it free
from oil, otherwise the transpar-
ency of the glass, the luminosity
of the bulb, and the bulb life will
be adversely affected. Thor-
oughly clean off any dirt and fin-
gerprints on the headlight bulb
using a cloth moistened with al-
cohol or thinner.
Headlight lens
Do not affix any type of tinted
film or stickers to the headlight
lens.
Do not use a headlight bulb of a
wattage higher than specified.
1. Remove the headlight unit by re-
moving the bolts on each side.
1. Headlight fuse
2. Signaling system fuse
3. Ignition fuse
4. Radiator fan motor fuse
5. Main fuse
6. ABS control unit fuse
7. Spare fuse
8. Backup fuse
9. ABS solenoid fuse
10.ABS motor fuse
Specified fuses:
Main fuse:
20.0 A
Ignition fuse:
7.5 A
Signaling system fuse:
7.5 A
Headlight fuse:
15.0 A
Radiator fan motor fuse:
5.0 A
ABS control unit fuse:
10.0 A
ABS motor fuse:
30.0 A
ABS solenoid fuse:
20.0 A
Backup fuse:
10.0 A
ZAUM1231
10
303020
7
8
91010
157.5
207.5 7.515
5 20
5
7
12
3
45
6
1. Do not touch the glass part of the bulb.
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Periodic maintenance and adjustment
6-37
6
EAU67131
Supporting the motorcycle
Since this model is not equipped with a
centerstand, use maintenance stands
when removing the front or rear wheel
or when performing other maintenance
that requires the motorcycle to stand
up right.
Check that the motorcycle is in a stable
and level position before starting any
maintenance.
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.
1. Maintenance stand (example)
1
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