2021 YAMAHA MT-125 fuel

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

Safety information
1-5
1operator and may limit control
ability, therefore, such accesso-
ries are not recommended.
 Use caution when adding electri-
cal accessories. If electrical ac-
cessories exceed the capacity of
the motorcycle’s electrical sys-
tem, an electric failure could re-
sult, which could cause a
dangerous loss of lights or engine
power.
Aftermarket Tires an d Rims
The tires and rims that came with your
motorcycle were designed to match
the performance capabilities and to
provide the best combination of han-
dling, braking, and comfort. Other
tires, rims, sizes, and combinations
may not be appropriate. See page 6-17
for tire specifications and for informa-
tion on servicing and replacing your
tires.
Transportin g the Motorcycle
Be sure to observe following instruc-
tions before transporting the motorcy-
cle in another vehicle. 
Remove all loose items from the
motorcycle.
 Check that the fuel cock (if
equipped) is in the off position and
that there are no fuel leaks.
 Shift the transmission into gear
(for models with a manual trans-
mission).
 Secure the motorcycle with tie-
downs or suitable straps that are
attached to solid parts of the mo-
torcycle, such as the frame or up-
per front fork triple clamp (and not,
for example, to rubber-mounted
handlebars or turn signals, or
parts that could break). Choose
the location for the straps carefully
so the straps will not rub against
painted surfaces during transport.
 The suspension should be com-
pressed somewhat by the tie-
downs, if possible, so that the mo-
torcycle will not bounce exces-
sively during transport.
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Description
2-1
2
EAU10411
Left view
1
2
3
4
6
5
7
98
1. Fuel tank cap (page 3-16)
2. Battery (page 6-30)
3. Fuses (page 6-31)
4. Tool kit (page 6-2)
5. Sidestand (page 3-20)
6. Air filter check hose
7. Shift pedal (page 3-14)
8. Idle adjusting screw (page 6-15)9. Coolant reservoir (page 6-13)
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Instrument and control functions
3-4
3
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, have a Yamaha dealer check the
vehicle.
EAUM4011
Multi-function meter unit
WARNING
EWA12423
Be sure to stop the vehicle before
makin g any settin g chan ges to the
multi-function meter unit. Chan gin g
settin gs while ri din g can distract the
operator an d increase the risk of an
acci dent.The multi-function meter unit is
equipped with the following:
 a speedometer
 a clock
 a fuel meter
 a VVA indicator
 a tachometer 
a transmission gear display
 a multi-function display
 a shift timing indicator light
 a self diagnostic device
TIPExcept when accessing the
brightness screen and shift timing
indicator light control mode or
when displaying the welcome
screen, the key must be turned
to “ ” before you can use the
“SELECT” and “RESET” buttons
to adjust the multi-function meter.
 For the UK: To switch between ki-
lometers and miles, press and
hold the “SELECT” button.
1. “SELECT” button
2. “RESET” buttonZAUM1567
1
2
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Instrument and control functions
3-5
3 Speed
ometer
The speedometer shows the vehicle’s
traveling speed.
Clock mo de
The clock uses a 12-hour time system. To set the clock
1. Push and hold the “SELECT” and
“RESET” button together.
2. When the hour digits start flash- ing, use the “RESET” button to set
the hours.
3. Push the “SELECT” button and the minutes will start flashing.
4. Use the “RESET” button to set the minutes.
5. Push the “SELECT” button to start the clock.
Fuel meter
The fuel meter indicates the amount of
fuel in the fuel tank. The display seg-
ments of the fuel meter disappear to-
wards “E” (empty) as the fuel level decreases. When the last segment
start flashing, refuel as soon as possi-
ble.
When the key is turned to “ ”, the dis-
play segments of the fuel meter will
sweep once across the fuel level range
and then return to the current amount
in order to test the electrical circuit.
TIPThe fuel meter is equipped with a self-
diagnostic function. If a problem is de-
tected in the fuel meter electrical cir-
cuit, the fuel meter will flash
repeatedly. If this occurs, have a
Yamaha dealer check the vehicle.VVA in dicator
1. Speedometer
1. ClockZAUM1568
1
ZAUM1569
1
1. Fuel meterZAUM1570
1
1. VVA (variable valve actuation) indicatorZAUM1571
1
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Instrument and control functions
3-6
3
This model is equipped with variable
valve actuation (VVA) for good fuel
economy and acceleration in both the
low-speed and high-speed ranges.
The VVA indicator comes on when the
variable valve actuation system has
switched to the high-speed range.
Tachometer
The tachometer allows the rider to
monitor the engine speed and keep it
within the ideal power range.
NOTICE
ECA23050
Do not operate the en
gine in the ta-
chometer hi gh-r/min zone. Hi
gh-r/min zone: 11000 r/min an d
a b ove
Transmission gear display
This display shows the selected gear.
The neutral position is indicated by “ ”
and by the neutral indicator light. Multi-function
display
The multi-function display is equipped
with the following:  an odometer
 two tripmeters
 a fuel reserve tripmeter
 an instantaneous fuel consump-
tion display
 an average fuel consumption dis-
play
 an average speed display
 a brightness screen and shift tim-
ing indicator light control mode
 welcome screen display
 a self diagnostic device
Push the “SELECT” button to switch
the display between the odometer
mode “ODO”, tripmeters mode “TRIP
1. Tachometer
2. Tachometer red zoneZAUM1572
1 2
1. Neutral indicator light “ ”
2. Transmission gear displayZAUM15731
2
1. Multi-function displayZAUM1574
1
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Instrument and control functions
3-7
3 1” and “TRIP 2”, instantaneous fuel
consumption mode “km/L” or “L/100
km”, average fuel consumption mode
“AVE_ _._ km/L” or “AVE_ _._ L/100
km” and average speed mode “AVE_
_._ km/h” in the following order:
ODO
→ TRIP 1 → TRIP 2 → km/L or
L/100 km → AVE_ _._ km/L or AVE_ _._
L/100 km → AVE_ _._ km/h → ODO
For the UK:
Push the “SELECT” button to switch
the display between the odometer
mode “ODO”, tripmeters mode “TRIP
1” and “TRIP 2”, instantaneous fuel
consumption mode “km/L” or “L/100
km” or “MPG”, average fuel consump-
tion mode “AVE_ _._ km/L”, “AVE_ _._
L/100 km” or “AVE_ _ _._ MPG” and
average speed mode “AVE_ _._ km/h”
or “AVE_ _._ MPH” in the following or-
der:
ODO → TRIP 1 → TRIP 2 → km/L or
L/100 km or MPG → AVE_ _._ km/L or
AVE_ _._ L/100 km or AVE_ _ _._
MPG → AVE_ _._ km/h or AVE_ _._
MPH → ODO Push the “RESET” button to switch
display backward.
If the last segment of the fuel meter
starts flashing, the display automati-
cally changes to the fuel reserve trip-
meter mode “TRIP F” and starts
counting the distance traveled from
that point. In that case, push the “SE-
LECT” button to switch the display be-
tween the various tripmeter, odometer,
instantaneous fuel consumption, aver-
age fuel consumption, and average
speed modes in the following order:
TRIP F
→ km/L or L/100 km → AVE_
_._ km/L or AVE_ _._ L/100 km → AVE_
_._ km/h → ODO → TRIP 1 → TRIP 2
→ TRIP F
For the UK:
TRIP F → km/L, L/100 km or MPG →
AVE_ _._ km/L, AVE_ _._ L/100 km or
AVE_ _ _._ MPG → AVE_ _._ km/h or
AVE_ _._ MPH → ODO → TRIP 1 →
TRIP 2 → TRIP F To reset a tripmeter, select it by push-
ing the “SELECT” button and then
push and hold the “RESET” button.
If you do not reset the fuel reserve trip-
meter manually, it resets itself auto-
matically and the display returns to the
prior mode after refueling and traveling
5 km (3 mi).
O
dometer mo de
The odometer shows the total distance
traveled by the vehicle. It will lock at
999999 and cannot be reset.
1. OdometerZAUM1575
1
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Instrument and control functions
3-8
3
Tripmeters mo
de
The tripmeters shows the total dis-
tance traveled since they were last re-
set.
To reset a tripmeter, push and hold the
“RESET” button.
TIP The tripmeters will reset and con-
tinue counting after 9999.9 is
reached. To reset the tripmeters,
while it is being displayed, push
and hold the “RESET” button.
Instantaneous fuel consumption
mo de
Shows the current fuel consumption
when the vehicle is traveling at least 10
km/h (6 mi/h).
The instantaneous fuel consumption
can be set to either “km/L”, “L/100 km”
or “MPG” (for the UK).
To switch the instantaneous fuel con-
sumption display between “km/L”,
“L/100 km” and “MPG” (for the UK),
push and hold the “SELECT” button.  “km/L”: The distance that can be
traveled on 1.0 L of fuel under the
current riding conditions is shown. 
“L/100 km”: The amount of fuel
necessary to travel 100 km under
the current riding conditions is
shown.
 “MPG” (for the UK): The distance
that can be traveled on
1.0 Imp.gal of fuel under the cur-
rent riding conditions is shown.
TIPIf traveling at speeds under 10
km/h (6 mi/h), “_ _._” is displayed.
 The instantaneous fuel consump-
tion function should be used for
general reference only. Do not use
this figure to estimate the distance
that can be traveled on the current
tank of fuel.
1. TripmeterZAUM1576
1
1. Instantaneous fuel consumption displayZAUM1577
1
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