YAMAHA MT-125 2021 Owners Manual

PANTONE285C
MTN125-A (MT-125)
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B6G-F8199-E1
Read this manual carefully
before operating this vehicle.
MOTORCYCLE
OWNER’S MANUAL
Specifications
Consumer information
Motorcycle care and storage
Periodic maintenance and adjustment
For your safety – pre-operation checks
Instrument and control functions Description
Safety information
Operation and important riding points
Index
[English (E)]

EAU46094
Read this manual carefully before operatin g this vehicle. This manual shoul d stay with this vehicle if it is sol d.
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Introduction
EAU10103
Welcome to the Yamaha world of motorcycling!
As the owner of the MTN125-A, you are benefiting from Yamaha’s vast experience and newest technology regarding the
design and manufacture of high-quality products, which have earned Yamaha a reputation for dependability.
Please take the time to read this manual thoroughly, so as to enjoy all advantages of your MTN125-A. The Owner’s Manual
does not only instruct you in how to operate, inspect and maintain your motorcycle, but also in how to safeguard yourself
and others from trouble and injury.
In addition, the many tips given in this manual will help keep your motorcycle in the best possible condition. If you have any
further questions, do not hesitate to contact your Yamaha dealer.
The Yamaha team wishes you many safe and pleasant rides. So, remember to put safety first!
Yamaha continually seeks advancements in product design and quality. Therefore, while this manual contains the most cur- rent product information available at the time of printing, there may be minor discrepancies between your motorcycle and
this manual. If there is any question concerning this manual, please consult a Yamaha dealer.
WARNING
EWA10032
Please rea d this manual carefully an d completely before operatin g this motorcycle.
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Important manual information
EAU10134
Particularly important information is distinguished in this manual by the following notations:
*Product and specifications are subject to change without notice.This is the safety alert sym
bol. It is use d to alert you to potential personal injury
hazar ds. Ob ey all safety messa ges that follow this sym bol to avoi d possi ble injury
or death.
A WARNING in dicates a hazar dous situation which, if not avoi ded , coul d result in
d eath or serious injury.
A NOTICE in dicates special precautions that must be taken to avoi d d ama ge to the
vehicle or other property.
A TIP provides key information to make procedures easier or clearer.
WARNING
NOTICETIP
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Important manual information
EAUM1013
MTN125-A
OWNER’S MANUAL
©2021 by MBK INDUSTRIE
1st e dition, Septem ber 2020
All ri ghts reserve d
Any reprintin g or unauthorize d use
without the written permission of
MBK INDUSTRIE
is expressly prohi bite d.
Printe d in France.
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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

Table of contents
Battery ...........................................6-30
Replacing the fuses .......................6-31
Vehicle lights .................................6-32
Tail/brake light ...............................6-32
Replacing a turn signal light
bulb ............................................6-33
Replacing the license plate light bulb ............................................6-33
Supporting the motorcycle............6-34
Troubleshooting ............................6-34
Troubleshooting chart ...................6-35
Motorcycle care an d stora ge ..........7-1
Matte color caution .........................7-1
Care .................................................7-1
Storage ............................................7-3
Specifications ....................................8-1
Consumer information .....................9-1
Identification numbers .....................9-1
Diagnostic connector ......................9-2
Vehicle data recording ....................9-2
In dex ................................................10-1
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1-1
1
Safety information
EAU1028C
Be a Responsible Owner
As the vehicle’s owner, you are re-
sponsible for the safe and proper oper-
ation of your motorcycle.
Motorcycles are single-track vehicles.
Their safe use and operation are de-
pendent upon the use of proper riding
techniques as well as the expertise of
the operator. Every operator should
know the following requirements be-
fore riding this motorcycle.
He or she should:  Obtain thorough instructions from
a competent source on all aspects
of motorcycle operation.
 Observe the warnings and mainte-
nance requirements in this Own-
er’s Manual.
 Obtain qualified training in safe
and proper riding techniques.
 Obtain professional technical ser-
vice as indicated in this Owner’s
Manual and/or when made neces-
sary by mechanical conditions. 
Never operate a motorcycle with-
out proper training or instruction.
Take a training course. Beginners
should receive training from a cer-
tified instructor. Contact an autho-
rized motorcycle dealer to find out
about the training courses nearest
you.
Safe Ri din g
Perform the pre-operation checks
each time you use the vehicle to make
sure it is in safe operating condition.
Failure to inspect or maintain the vehi-
cle properly increases the possibility of
an accident or equipment damage.
See page 4-1 for a list of pre-operation
checks.  This motorcycle is designed to
carry the operator and a passen-
ger.
 The failure of motorists to detect
and recognize motorcycles in traf-
fic is the predominating cause of
automobile/motorcycle accidents.
Many accidents have been
caused by an automobile driver
who did not see the motorcycle.
Making yourself conspicuous ap- pears to be very effective in reduc-
ing the chance of this type of
accident.
Therefore:
• Wear a brightly colored jacket.
• Use extra caution when you are approaching and passing
through intersections, since in-
tersections are the most likely
places for motorcycle accidents
to occur.
• Ride where other motorists can see you. Avoid riding in another
motorist’s blind spot.
• Never maintain a motorcycle without proper knowledge.
Contact an authorized motorcy-
cle dealer to inform you on ba-
sic motorcycle maintenance.
Certain maintenance can only
be carried out by certified staff.UB6GE1E0.book Page 1 Thursday, July 30, 2020 1:08 PM

Safety information
1-2
1

Many accidents involve inexperi-
enced operators. In fact, many op-
erators who have been involved in
accidents do not even have a cur-
rent motorcycle license.
• Make sure that you are qualified and that you only lend your mo-
torcycle to other qualified oper-
ators.
• Know your skills and limits. Staying within your limits may
help you to avoid an accident.
• We recommend that you prac- tice riding your motorcycle
where there is no traffic until you
have become thoroughly famil-
iar with the motorcycle and all of
its controls.
 Many accidents have been
caused by error of the motorcycle
operator. A typical error made by
the operator is veering wide on a
turn due to excessive speed or un-
dercornering (insufficient lean an-
gle for the speed).
• Always obey the speed limit and never travel faster than warrant-
ed by road and traffic condi-
tions. • Always signal before turning or
changing lanes. Make sure that
other motorists can see you.
 The posture of the operator and
passenger is important for proper
control.
• The operator should keep both hands on the handlebar and
both feet on the operator foot-
rests during operation to main-
tain control of the motorcycle.
• The passenger should always hold onto the operator, the seat
strap or grab bar, if equipped,
with both hands and keep both
feet on the passenger footrests.
Never carry a passenger unless
he or she can firmly place both
feet on the passenger footrests.
 Never ride under the influence of
alcohol or other drugs.
 This motorcycle is designed for
on-road use only. It is not suitable
for off-road use. Protective Apparel
The majority of fatalities from motorcy-
cle accidents are the result of head in-
juries. The use of a safety helmet is the
single most critical factor in the pre-
vention or reduction of head injuries.
 Always wear an approved helmet.
 Wear a face shield or goggles.
Wind in your unprotected eyes
could contribute to an impairment
of vision that could delay seeing a
hazard.
 The use of a jacket, heavy boots,
trousers, gloves, etc., is effective
in preventing or reducing abra-
sions or lacerations.
 Never wear loose-fitting clothes,
otherwise they could catch on the
control levers, footrests, or wheels
and cause injury or an accident.
 Always wear protective clothing
that covers your legs, ankles, and
feet. The engine or exhaust sys-
tem become very hot during or af-
ter operation and can cause
burns.
 A passenger should also observe
the above precautions.
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Safety information
1-3
1Avoi
d Car bon Monoxi de Poisonin g
All engine exhaust contains carbon
monoxide, a deadly gas. Breathing
carbon monoxide can cause head-
aches, dizziness, drowsiness, nausea,
confusion, and eventually death.
Carbon Monoxide is a colorless, odor-
less, tasteless gas which may be pres-
ent even if you do not see or smell any
engine exhaust. Deadly levels of car-
bon monoxide can collect rapidly and
you can quickly be overcome and un-
able to save yourself. Also, deadly lev-
els of carbon monoxide can linger for
hours or days in enclosed or poorly
ventilated areas. If you experience any
symptoms of carbon monoxide poi-
soning, leave the area immediately, get
fresh air, and SEEK MEDICAL TREAT-
MENT.  Do not run engine indoors. Even if
you try to ventilate engine exhaust
with fans or open windows and
doors, carbon monoxide can rap-
idly reach dangerous levels.
 Do not run engine in poorly venti-
lated or partially enclosed areas
such as barns, garages, or car-
ports. 
Do not run engine outdoors where
engine exhaust can be drawn into
a building through openings such
as windows and doors.
Loa din g
Adding accessories or cargo to your
motorcycle can adversely affect stabil-
ity and handling if the weight distribu-
tion of the motorcycle is changed. To
avoid the possibility of an accident, use
extreme caution when adding cargo or
accessories to your motorcycle. Use
extra care when riding a motorcycle
that has added cargo or accessories.
Here, along with the information about
accessories below, are some general
guidelines to follow if loading cargo to
your motorcycle:
The total weight of the operator, pas-
senger, accessories and cargo must
not exceed the maximum load limit.
Operation of an overloa ded vehicle
coul d cause an acci dent. When loading within this weight limit,
keep the following in mind:
 Cargo and accessory weight
should be kept as low and close to
the motorcycle as possible. Se-
curely pack your heaviest items as
close to the center of the vehicle
as possible and make sure to dis-
tribute the weight as evenly as
possible on both sides of the mo-
torcycle to minimize imbalance or
instability.
 Shifting weights can create a sud-
den imbalance. Make sure that
accessories and cargo are se-
curely attached to the motorcycle
before riding. Check accessory
mounts and cargo restraints fre-
quently.
• Properly adjust the suspension for your load (suspension-ad-
justable models only), and
check the condition and pres-
sure of your tires.
• Never attach any large or heavy items to the handlebar, front
fork, or front fender. These
items, including such cargo as
sleeping bags, duffel bags, or
Maximum loa d:
178 kg (392 lb)
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