2021 YAMAHA MT-125 ABS

Table of contentsSafety information ............................ 1-1
Description ....................................... 2-1
Left view ......................................... 2-1
Right view ....................................... 2-2
Controls and instruments ............... 2-3
Instrument an d 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 .................................. 3-14
ABS .............................................. 3-15
Fuel tank cap ................................ 3-16
Fuel ............................................... 3-16
Fuel tank breather hose and overflow hose ............................ 3-18
Catalytic converter ....................... 3-19
Seat .............................................. 3-19
Helmet holder ............................... 3-20
Sidestand ..................................... 3-20
Ignition circuit cut-off system ....... 3-21 For your safety – pre-operation
checks
............................................... 4-1
Operation an d important ri din g
points ................................................. 5-1
Engine break-in ............................... 5-1
Starting the engine .......................... 5-2
Shifting ............................................ 5-3
Tips for reducing fuel consumption ................................ 5-4
Parking ............................................ 5-4
Perio dic maintenance an d
a d justment ........................................ 6-1
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... 6-8
Checking the spark plug ................. 6-8
Canister ........................................... 6-9
Engine oil and oil filter element ..... 6-10
Why Yamalube .............................. 6-12
Coolant.......................................... 6-13
Replacing the air filter element
and cleaning the check hose..... 6-14
Adjusting the engine idling speed ......................................... 6-15
Adjusting the throttle grip free play ............................................ 6-16 Valve clearance............................. 6-16
Tires .............................................. 6-17
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 ...... 6-22
Changing the brake fluid .............. 6-24
Drive chain slack........................... 6-24
Cleaning and lubricating the drive chain.......................................... 6-25
Checking and lubricating the cables ........................................ 6-26
Checking and lubricating the
throttle grip and cable ............... 6-26
Checking and lubricating the brake and shift pedals............... 6-27
Checking and lubricating the brake and clutch levers ............. 6-27
Checking and lubricating the
sidestand................................... 6-28
Lubricating the rear suspension ... 6-28
Checking the front fork ................. 6-29
Checking the steering................... 6-29
Checking the wheel bearings ....... 6-30UB6GE1E0.book Page 1 Thursday, July 30, 2020 1:08 PM

Instrument and control functions
3-2
3
To unlock the steering
From the “LOCK” position, push the
key and turn it to “OFF”.
EAU4939N
In
dicator li ghts an d warnin g
lig hts
EAU11022
Turn si gnal in dicator li ght “ ”
This indicator light flashes when a turn
signal light is flashing.
EAU11061
Neutral in dicator li ght “ ”
This indicator light comes on when the
transmission is in the neutral position.
EAU11081
Hi gh beam in dicator li ght “ ”
This indicator light comes on when the
high beam of the headlight is switched
on.
EAU11449
Coolant temperature warnin g
li g ht “ ”
This warning light comes on when the
engine is overheating. If this occurs,
stop the engine immediately and allow
the engine to cool. (See page 6-36.)
For vehicles with a radiator fan, the ra-
diator fan(s) automatically switch on or
off according to the coolant tempera-
ture.TIPWhen the vehicle is turned on, the light
will come on for a few seconds, and
then go off. If the light does not come
on, or if the light remains on, have a
Yamaha dealer check the vehicle. NOTICE
ECA10022
Do not continue to operate the en-
g ine if it is overheatin g.
1. Push.
2. Turn.12
1. Shift light
2. Turn signal indicator light “ ”
3. High beam indicator light “ ”
4. Anti-lock Brake System (ABS) warning
light “ ”
5. Malfunction indicator light “ ”
6. Coolant temperature warning light “ ”
7. Neutral indicator light “ ”ZAUM15665 6 7
2
3
4
1
ABS
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Instrument and control functions
3-3
3
EAU88330
Malfunction in dicator li ght
(MIL) “ ”
This light comes on or flashes if a prob-
lem is detected in the engine or other
vehicle control system. If this occurs,
have a Yamaha dealer check the on-
board diagnostic system. The electri-
cal circuit of the warning light can be
checked by vehicle power on. The light
should come on for a few seconds,
and then go off. If the light does not
come on initially when the vehicle pow-
er on, or if the light remains on, have a
Yamaha dealer check the vehicle.NOTICE
ECA26820
If the MIL starts flashin g, re duce en-
g ine speed to prevent exhaust sys-
tem damag e.TIPThe engine is sensitively controlled for
the on-board diagnostic system to de-
tect deterioration and malfunction of
the emission control system. Due to
this specification, the MIL may come
on or flash for vehicle modifications,
lack of maintenance, or excessive or improper use of the motorcycle. To
prevent this, observe these precau-
tions.
 Do not attempt to modify the soft-
ware of the engine control unit.
 Do not add any electrical acces-
sories that interfere with engine
control.
 Do not use aftermarket accesso-
ries or parts such as suspension,
spark plugs, injectors, exhaust
system, etc.
 Do not change drivetrain specifi-
cations (chain, sprockets, wheels,
tires, etc.).
 Do not remove or alter the O2 sen-
sor, air induction system, or ex-
haust parts (catalysts or EXUP,
etc.).
 Maintain proper drive chain.
 Maintain correct tire pressure.
 Maintain proper brake pedal
height to prevent rear brake from
dragging.
 Do not operate the vehicle in an
extreme manner. For example, re-
peated or excessive opening and closing of the throttle, racing,
burnouts, wheelies, extended
half-clutch use, etc.
EAU69895
ABS warnin
g li ght “ ”
This warning light comes on when the
vehicle is first turned on, and goes off
after starting riding. If the warning light
comes on while riding, the anti-lock
brake system may not work correctly.
WARNING
EWA16043
If the ABS warnin g li ght does not
turn off after reachin g 10 km/h (6
mi/h), or if the warnin g li ght comes
on while ri din g:
 Use extra caution to avoi d pos-
si ble wheel lock d uring emer-
g ency brakin g.
 Have a Yamaha dealer check
the vehicle as soon as possi ble.
EAU80372
Shift li ght
This light can be set to come on and go
off at select engine speeds. (See page
3-10.)
ABS
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Instrument and control functions
3-15
3
EAU63040
ABSThe Yamaha ABS (Anti-lock Brake
System) features a dual electronic con-
trol system, which acts on the front and
rear brakes independently.
Operate the brakes with ABS as you
would conventional brakes. If the ABS
is activated, a pulsating sensation may
be felt at the brake lever or brake ped-
al. In this situation, continue to apply
the brakes and let the ABS work; do
not “pump” the brakes as this will re-
duce braking effectiveness.
WARNING
EWA16051
Always keep a sufficient d istance
from the vehicle ahea d to match the
ri din g speed even with ABS.
 The ABS performs best with
lon g b rakin g d istances.
 On certain surfaces, such as
rou gh or g ravel roa ds, the b rak-
in g d istance may b e longer with
the ABS than without.The ABS is monitored by an ECU,
which will revert the system to conven-
tional braking if a malfunction occurs.
TIP The ABS performs a self-diagno-
sis test each time the vehicle first
starts off after the key is turned to
“ON” and the vehicle has traveled
at a speed of 10 km/h (6 mi/h) or
higher. During this test, a “click-
ing” noise can be heard from the
hydraulic control unit, and if the
brake lever or brake pedal is even
slightly applied, a vibration can be
felt at the lever and pedal, but
these do not indicate a malfunc-
tion.
 This ABS has a test mode which
allows the owner to experience
the pulsation at the brake lever or
brake pedal when the ABS is op-
erating. However, special tools are
required, so please consult your
Yamaha dealer.NOTICE
ECA20100
Be careful not to damag e the wheel
sensor or wheel sensor rotor; other-
wise, improper performance of the
ABS will result.
1. Front wheel sensor rotor
2. Front wheel sensor
1. Rear wheel sensor
2. Rear wheel sensor rotorZAUM173412ZAUM1590
12
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Operation and important rid ing points
5-2
5
EAU86690
Startin g the eng ineThe ignition circuit cut-off system will
enable starting when:
 the transmission is in the neutral
position or
 the transmission is in gear, the
sidestand is up, and the clutch le-
ver is pulled.
To start the engine1. Turn the main switch on and set the engine stop switch to the run
position.
2. Confirm the indicator and warning light(s) come on for a few sec-
onds, and the go off. (See page
3-2.)TIPDo not start the engine if the en-
gine trouble warning light remains
on.
 The ABS warning light should
come on and stay on until the ve-
hicle reaches a speed of 10 km/h
(6 mi/h).
NOTICE
ECA24110
If a warnin g or in dicator li ght does
not work as d escribed a bove, have a
Yamaha dealer check the vehicle.3. Shift the transmission into the
neutral position.
4. Start the engine by pushing the start switch.
5. Release the start switch when the engine starts, or after 5 seconds.
Wait 10 seconds before pressing
the switch again to allow battery
voltage to restore.NOTICE
ECA11043
For maximum en gine life, never ac-
celerate har d when the en gine is
col d!
EAU45312
TIPThis model is equipped with a lean an-
gle sensor to stop the engine in case of
a turnover. In this case, turn the main
switch off and then on. Failing to do so
will prevent the engine from starting
even though the engine will crank
when pushing the start switch.
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Periodic maintenance an d a djustment
6-23
6
Rear
brake
WARNING
EWA16011
Improper maintenance can result in
loss of b raking a bility. O bserve
these precautions:  Insufficient brake flui d may al-
low air to enter the brake sys-
tem, re ducin g brakin g
performance.
 Clean the filler cap before re-
movin g. Use only DOT 4 brake
flui d from a seale d container. 
Use only the specified b rake flu-
i d ; otherwise, the ru bber seals
may deteriorate, causin g leak-
a g e.
 Refill with the same type of
brake flui d. A dding a brake fluid
other than DOT 4 may result in a
harmful chemical reaction.
 Be careful that water or d ust
d oes not enter the brake flui d
reservoir when refillin g. Water
will si gnificantly lower the boil-
in g point of the flui d an d may re-
sult in vapor lock, an d d ir
t may
clo g the ABS hy draulic unit
valves.
NOTICE
ECA17641
Brake flui d may d amage painte d
surfaces or plastic parts. Always
clean up spilled fluid imme diately.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 markSpecifie
d b rake flui d:
DOT 4
1
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Periodic maintenance an d a djustment
6-31
6
To char
ge the b attery
Have your Yamaha dealer charge the
battery if it seems to have discharged.
Keep in mind that the battery tends to
discharge more quickly if the vehicle is
equipped with optional electrical ac-
cessories.
NOTICE
ECA16522
To char ge a VRLA (Valve Re gulate d
Lea d Aci d) battery, a special (con-
stant-volta ge) battery char ger is re-
quire d. Usin g a conventional b attery
char ger will damag e the battery.To store the battery
1. If the vehicle will not be used for more than one month, remove the
battery, fully charge it, and then
place it in a cool, dry place.
NOTICE: When removin g the
b attery, be sure to turn the main
switch off, then disconnect the
ne gative lead before discon-
nectin g the positive lea d.
[ECA16304]
2. If the battery will be stored for
more than two months, check it at
least once a month and fully
charge it if necessary. 3. Fully charge the battery before in-
stallation. NOTICE: When install-
in g the b attery, be sure to turn
the main switch off, then con-
nect the positive lea d before
connectin g the ne gative lea d.
[ECA16842]
4. After installation, make sure that
the battery leads are properly con-
nected to the battery terminals.NOTICE
ECA16531
Always keep the b attery charged .
Storin g a dischar ged battery can
cause permanent b attery damag e.
EAUB1116
Replacin g the fusesThe fuse box is located under the seat.
(See page 3-19.)
If a fuse is blown, replace it as follows.
1. Turn the main switch off and turn off the electrical circuit in ques-
tion.
2. Remove the blown fuse, and then install a new fuse of the specified
amperage. WARNING! Do not
use a fuse of a hi gher ampera ge1. Fuse box
2. Spare fuse
3. Headlight fuse
4. ABS control unit fuse
5. Main fuse
6. ABS solenoid fuse
7. ABS motor fuse
8. Fuse tongs
15
7.5
2
1
5
7
.5
1
5
3
0
30
2
1
8
76
543
2
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Periodic maintenance an d a djustment
6-32
6 ratin
g than recommen ded to
avoi d causin g extensive d am-
a g e to the electrical system an d
possi bly a fire.
[EWA15132]
3. Turn the main switch 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.
EAUN2261
Vehicle lig htsThis model is equipped with LED lights
for headlights, auxiliary lights and
brake/tail light. If a light does not come
on, check the fuse and then have a
Yamaha dealer check the vehicle.NOTICE
ECA16581
Do not affix any type of tinte d film or
stickers to the hea dlig ht lens.
EAU24182
Tail/ brake li ghtThis 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.
Specifie d fuses:
Main fuse: 15.0 A
ABS motor fuse:
30.0 A
ABS solenoid fuse: 15.0 A
ABS control unit fuse: 2.0 A
Headlight fuse:
7.5 A
1. Auxiliary light
2. Headlight
2 1
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