2020 YAMAHA MT-125 engine

Instrument and control functions
3-18
3
EAU58301
Fuel tank overflow hose
Before operating the vehicle:
Check the fuel tank overflow hose
connection and routing.
Check the fuel tank overflow hose
for cracks or damage, and replace
it if necessary.
Make sure that the fuel tank over-
flow hose is not blocked, and
clean it if necessary.
EAU13435
Catalytic converter
The exhaust system contains catalytic
converter(s) to reduce harmful exhaust
emissions.
WARNING
EWA10863
The exhaust system is hot after op-
eration. To prevent a fire hazard or
burns:
Do not park the vehicle near
possible fire hazards such as
grass or other materials that
easily burn.
Park the vehicle in a place
where pedestrians or children
are not likely to touch the hot
exhaust system.
Make sure that the exhaust sys-
tem has cooled down before
doing any maintenance work.
Do not allow the engine to idle
more than a few minutes. Long
idling can cause a build-up of
heat.
1. Fuel tank overflow hose
1
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Instrument and control functions
3-21
3
EAU83150
Ignition circuit cut-off system
This 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.
The neutral 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.
The clutch switch may not be working.
The motorcycle should not be ridden
until checked by a Yamaha dealer.
WARNING
If a malfunction is found, have the
vehicle inspected before riding.
YES NO
YES NO
YES NO
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For your safety – pre-operation checks
4-1
4
EAU63441
Inspect your vehicle each time you use it to make sure the vehicle is in safe oper-
ating condition. Always follow the inspection and maintenance procedures and
schedules described in the Owner’s Manual.
WARNING
EWA11152
Failure to inspect or maintain the vehicle properly increases the possibility
of an accident or equipment damage. Do not operate the vehicle if you find
any problem. If a problem cannot be corrected by the procedures provided
in this manual, have the vehicle inspected by a Yamaha dealer.
Before using this vehicle, check the following points:
ITEM CHECKS PAGE
Fuel• Check fuel level in fuel tank.
• Refuel if necessary.
• Check fuel line for leakage.
• Check fuel tank overflow hose for obstructions, cracks
or damage, and check hose connection.3-16,
3-18
Engine oil• Check oil level in engine.
• If necessary, add recommended oil to specified level.
• Check vehicle for oil leakage.6-8
Coolant• Check coolant level in reservoir.
• If necessary, add recommended coolant to specified
level.
• Check cooling system for leakage.6-11
Front 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.6-21,
6-22
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.6-21,
6-22
Clutch• Check operation.
• Lubricate cable if necessary.
• Check lever free play.
• Adjust if necessary.6-18
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Operation and important riding points
5-1
5
EAU15952
Read the Owner’s Manual carefully to
become familiar with all controls. If
there is a control or function you do not
understand, ask your Yamaha dealer.
WARNING
EWA10272
Failure to familiarize yourself with
the controls can lead to loss of con-
trol, which could cause an accident
or injury.
EAU16831
Engine break-in
There is never a more important period
in the life of your engine than the period
between 0 and 1000 km (600 mi). For
this reason, you should read the fol-
lowing material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The various parts in
the engine wear and polish themselves
to the correct operating clearances.
During this period, prolonged full-throt-
tle operation or any condition that
might result in engine overheating
must be avoided.
EAU16983
0–500 km (0–300 mi)
Avoid prolonged operation above 5000
r/min.
After every hour of operation, stop the
engine, and then let it cool for five to
ten minutes.
Vary the engine speed from time to
time. Do not operate the engine at one
set throttle position.
500–1000 km (300–600 mi)
Avoid prolonged operation above 7500
r/min.
Rev the engine freely through the
gears, but do not use full throttle at any
time. NOTICE: After 1000 km (600 mi)
of operation, the engine oil must be
changed, the oil filter cartridge or el-
ement replaced, and the oil strainer
cleaned.
[ECA10322]
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Operation and important riding points
5-2
51000 km (600 mi) and beyond
The vehicle can now be operated nor-
mally.
NOTICE
ECA10311
Keep the engine speed out of
the tachometer red zone.
If any engine trouble should oc-
cur during the engine break-in
period, immediately have a
Yamaha dealer check the vehi-
cle.
EAU86690
Starting the engine
The 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 engine
1. 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 warning or indicator light does
not work as described above, 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.
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Operation and important riding points
5-3
5
NOTICE
ECA11043
For maximum engine life, never ac-
celerate hard when the engine is
cold!
EAU45312
TIP
This 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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Operation and important riding points
5-4
5
EAU16674
Shifting
Shifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing hills,
etc.
The gear positions are shown in the il-
lustration.
TIP
To shift the transmission into the neu-
tral position ( ), press the shift pedal
down repeatedly until it reaches the
end of its travel, and then slightly raise
it.
NOTICE
ECA10261
Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long dis-
tances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.
Always use the clutch while
changing gears to avoid dam-
aging the engine, transmission,and drive train, which are not
designed to withstand the
shock of forced shifting.
EAU85370To start out and accelerate
1. Pull the clutch lever to disengage
the clutch.
2. Shift the transmission into first
gear. The neutral indicator light
should go out.
3. Open the throttle gradually, and at
the same time, release the clutch
lever slowly.
4. After starting out, close the throt-
tle, and at the same time, quickly
pull the clutch lever in.
5. Shift the transmission into second
gear. (Make sure not to shift the
transmission into the neutral posi-
tion.)
6. Open the throttle part way and
gradually release the clutch lever.
7. Follow the same procedure when
shifting to the next higher gear.
EAU85380To decelerate
1. Release the throttle and apply
both the front and the rear brakes
smoothly to slow the motorcycle.
2. As the vehicle decelerates, shift to
a lower gear.
3. When the engine is about to stall
or runs roughly, pull the clutch le-
ver in, use the brakes to slow the
motorcycle, and continue to
downshift as necessary.
4. Once the motorcycle has
stopped, the transmission can be
shifted into the neutral position.
1. Neutral position
2. Shift pedal
1 2 3 4 5
6
1
2 N
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