2021 YAMAHA MT-125 clutch

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

Description
2-3
2
EAU10431
Controls and instruments
1
2
3
4
5
6
7
8
1. Clutch lever (page 3-13)
2. Left handlebar switches (page 3-12)
3. Multi-function meter unit (page 3-4)
4. Main switch/steering lock (page 3-1)
5. Front brake fluid reservoir (page 6-22)
6. Right handlebar switches (page 3-12)
7. Throttle grip (page 6-16)
8. Brake lever (page 3-14)
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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
3-13
3
EAU12352
Pass switch “ ”
Press this switch to flash the headlight.TIPWhen the dimmer switch is set
to “ ”, the passing switch has no ef-
fect.
EAU12402
Dimmer switch “ / ”
Set this switch to “ ” for the high
beam and to “ ” for the low beam.
EAU12461
Turn si gnal switch “ / ”
To signal a right-hand turn, push this
switch to “ ”. To signal a left-hand
turn, push this switch to “ ”. When
released, the switch returns to the cen-
ter position. To cancel the turn signal
lights, push the switch in after it has re-
turned to the center position.
EAU12501
Horn switch “ ”
Press this switch to sound the horn.
EAU68271
Start/En gine stop switch “ / / ”
To crank the engine with the starter,
set this switch to “ ”, and then slide
the switch toward “ ”. See page 5-2
for starting instructions prior to starting
the engine.
Set this switch to “ ” to stop the en-
gine in case of an emergency, such as
when the vehicle overturns or when the
throttle cable is stuck.
EAU12823
Clutch leverTo disengage the drivetrain from the
engine, such as when shifting gears,
pull the clutch lever toward to the han-
dlebar. Release the lever to engage the
clutch and transmit power to the rear
wheel.TIPThe lever should be pulled rapidly and
released slowly for smooth shifting.
(See page 5-3.)1. Clutch lever1
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Instrument and control functions
3-21
3 this system reg
ularly and have a
Yamaha dealer repair it if it does not
function properly.
EAU44895
I g nition circuit cut-off systemThis system prevents in-gear engine
starts unless the clutch lever is pulled
and the sidestand is up. Also, it will
stop the running engine should the
sidestand be lowered while the trans-
mission is in gear.
Periodically check the system via the
following procedure.TIP This check is most reliable if per-
formed with a warmed-up engine.
 See pages 3-1 and 3-12 for switch
operation information.
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Instrument and control functions
3-22
3
With the engine turned off:
1. Move the sidestand down.
2. Set engine stop switch to run position.
3. Turn main switch to on position.
4. Shift transmission into neutral.
5. Push the start switch.
Does the engine start?
With the engine still running:
6. Move the sidestand up.
7. Pull the clutch lever.
8. Shift transmission into gear.
9. Move the sidestand down.
Does the engine stall?
After the engine has stalled:
10. Move the sidestand up.
11. Pull the clutch lever.
12. Push the start switch.
Does the engine start?
The system is OK. The motorcycle can be ridden.
YES NO YES NO YES NO
The neutral switch may not be working.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
The clutch switch may not be working.
The motorcycle should not be ridden until
checked by a Yamaha dealer.The sidestand switch may not be working.
The motorcycle should not be ridden until
checked by a Yamaha dealer.If a malfunction is found, have the vehicle
inspected before riding.
WARNING
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For your safety – pre-operation checks
4-2
4
Rear brake • Check operation.
• If soft or spongy, have Yamaha dealer bleed hydraulic system.
• Check brake pads for wear.
• Replace if necessary.
• Check fluid level in reservoir.
• If necessary, add specified brake fluid to specified level.
• Check hydraulic system for leakage. 6-22, 6-22
Clutch • Check operation.
• Lubricate cable if necessary.
• Check lever free play.
• Adjust if necessary.
6-19
Throttle grip • Make sure that operation is smooth.
• Check throttle grip free play.
• If necessary, have Yamaha dealer adjust throttle grip free play and lubricate ca-
ble and grip housing. 6-16, 6-26
Control ca bles • 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, 6-25
Wheels an d tires • Check for damage.
• Check tire condition and tread depth.
• Check air pressure.
• Correct if necessary.
6-17, 6-19
Brake an d shift pe dals • Make sure that operation is smooth.
• Lubricate pedal pivoting points if necessary. 6-27
Brake an d clutch levers • Make sure that operation is smooth.
• Lubricate lever pivoting points if necessary.
6-27
Si destan d • Make sure that operation is smooth.
• Lubricate pivot if necessary.
6-28
ITEM CHECKS PAGE
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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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