2020 YAMAHA MT-125 engine oil

Periodic maintenance and adjustment
6-10
67. Install the oil filter element cover
by installing the bolts, then tight-
ening them to the specified
torque.
TIP
Make sure that the O-ring is properly
seated.
8. Install the engine oil strainer, com-
pression spring, O-ring and the
engine oil drain bolt, and then
tighten it to the specified torque.
NOTICE: Before installing the
engine oil drain bolt, do not for-
get to install the O-ring, com-
pression spring, and oil strainer
in position.
[ECA10422]
9. Refill with the specified amount of
the recommended engine oil, and
then install and tighten the oil filler
cap.
NOTICE
ECA11621
In order to prevent clutch slip-
page (since the engine oil also
lubricates the clutch), do not
mix any chemical additives. Do
not use oils with a diesel speci-
fication of “CD” or oils of a high-
er quality than specified. In
addition, do not use oils labeled
“ENERGY CONSERVING II” or
higher.
Make sure that no foreign mate-
rial enters the crankcase.
10. Start the engine, and then let it idle
for several minutes while checking
it for oil leakage. If oil is leaking,
immediately turn the engine off
and check for the cause.
11. Turn the engine off, and then
check the oil level and correct it if
necessary.
1. Oil filter element
2. O-ring
Tightening torque:
Oil filter element cover bolt:
10 N·m (1.0 kgf·m, 7.4 lb·ft)
Tightening torque:
Engine oil drain bolt:
32 N·m (3.2 kgf·m, 24 lb·ft)
Recommended engine oil:
See page 8-1.
Oil quantity:
Oil change:
0.85 L (0.90 US qt, 0.75 Imp.qt)
With oil filter removal:
0.95 L (1.00 US qt, 0.84 Imp.qt)
UB6GE0E0.book Page 10 Wednesday, August 28, 2019 11:11 AM

Periodic maintenance and adjustment
6-11
6
EAU85450
Why Yamalube
YAMALUBE oil is a Genuine YAMAHA
Part born of the engineers’ passion
and belief that engine oil is an impor-
tant liquid engine component. We form
teams of specialists in the fields of me-
chanical engineering, chemistry, elec-
tronics and track testing, and have
them develop the engine together with
the oil it will use. Yamalube oils take full
advantage of the base oil’s qualities
and blend in the ideal balance of addi-
tives to make sure the final oil clears
our performance standards. Thus,
Yamalube mineral, semisynthetic and
synthetic oils have their own distinct
characters and value. Yamaha’s expe-
rience gained over many years of re-
search and development into oil since
the 1960’s helps make Yamalube the
best choice for your Yamaha engine.
EAU20071
Coolant
The coolant level should be checked
before each ride. In addition, the cool-
ant must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
EAUE4091To check the coolant level
1. Place the vehicle on a level sur-
face.
2. Remove cowling A. (See page
6-7.)
3. Hold the vehicle in an upright po-
sition.
TIP
The coolant level must be
checked on a cold engine since
the level varies with engine tem-
perature.
Make sure that the vehicle is posi-
tioned straight up when checking
the coolant level. A slight tilt to the
side can result in a false reading.
4. Check the coolant level in the
coolant reservoir.
TIP
The coolant should be between the
minimum and maximum level marks.
UB6GE0E0.book Page 11 Wednesday, August 28, 2019 11:11 AM

Periodic maintenance and adjustment
6-25
6
EAU23026
Cleaning and lubricating the
drive chain
The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.
NOTICE
ECA10584
The drive chain must be lubricated
after washing the motorcycle, riding
in the rain or riding in wet areas.
1. Clean the drive chain with kero-
sene and a small soft brush.
NOTICE: To prevent damaging
the O-rings, do not clean the
drive chain with steam cleaners,
high-pressure washers or inap-
propriate solvents.
[ECA11122]
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant. NOTICE: Do not use
engine oil or any other lubri-
cants for the drive chain, as they
may contain substances that
could damage the O-rings.
[ECA11112]EAU23098
Checking and lubricating the
cables
The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubri-
cated if necessary. If a cable is
damaged or does not move smoothly,
have a Yamaha dealer check or re-
place it. WARNING! Damage to the
outer housing of cables may result
in internal rusting and cause inter-
ference with cable movement. Re-
place damaged cables as soon as
possible to prevent unsafe condi-
tions.
[EWA10712]
Recommended lubricant:
Yamaha cable lubricant or other
suitable cable lubricant
UB6GE0E0.book Page 25 Wednesday, August 28, 2019 11:11 AM

Motorcycle care and storage
7-3
72. For drive chain-equipped models:
Dry and then lubricate the drive
chain to prevent rust.
3. Use a chrome polish to shine
chrome, aluminum, and stainless
steel parts. Often the thermally in-
duced discoloring of stainless
steel exhaust systems can be re-
moved through polishing.
4. Apply a corrosion protection spray
on all metal parts including
chrome or nickel-plated surfaces.
WARNING! Do not apply silicone
or oil spray to seats, hand grips,
rubber foot pegs or tire treads.
Otherwise these parts will be-
come slippery, which could
cause loss of control. Thor-
oughly clean the surfaces of
these parts before operating the
vehicle. [EWA20650]
5. Treat rubber, vinyl, and unpainted
plastic parts with a suitable care
product.
6. Touch up minor paint damage
caused by stones, etc.
7. Wax all painted surfaces using a
non-abrasive wax or use a detail
spray for motorcycles.
8. When finished cleaning, start the
engine and let it idle for several
minutes to help dry any remaining
moisture.
9. If the headlight lens has fogged
up, start the engine and turn on
the headlight to help remove the
moisture.
10. Let the vehicle dry completely be-
fore storing or covering it.
NOTICE
ECA26320
Do not apply wax to rubber or
unpainted plastic parts.
Do not use abrasive polishing
compounds as they will wear
away the paint.
Apply sprays and wax sparingly.
Wipe off excess afterwards.
WARNING
EWA20660
Contaminants left on the brakes or
tires can cause loss of control.
Make sure there is no lubricant
or wax on the brakes or tires.
If necessary, wash the tires with
warm water and a mild deter-
gent.
If necessary, clean the brake
discs and pads with brake
cleaner or acetone.
Before riding at higher speeds,
test the vehicle’s braking per-
formance and cornering behav-
ior.
UB6GE0E0.book Page 3 Wednesday, August 28, 2019 11:11 AM

Motorcycle care and storage
7-4
7
EAU83472
Storage
Always store the vehicle in a cool, dry
place. If necessary, protect it against
dust with a porous cover. Be sure the
engine and the exhaust system are
cool before covering the vehicle. If the
vehicle often sits for weeks at a time
between uses, the use of a quality fuel
stabilizer is recommended after each
fill-up.
NOTICE
ECA21170
Storing the vehicle in a poorly
ventilated room or covering it
with a tarp, while it is still wet,
will allow water and humidity to
seep in and cause rust.
To prevent corrosion, avoid
damp cellars, stables (because
of the presence of ammonia)
and areas where strong chemi-
cals are stored.
Long term storage
Before storing the vehicle long term (60
days or more):
1. Make all necessary repairs and
perform any outstanding mainte-
nance.
2. Follow all instructions in the Care
section of this chapter.
3. Fill up the fuel tank, adding fuel
stabilizer according to product in-
structions. Run the engine for 5
minutes to distribute treated fuel
through the fuel system.
4. For vehicles equipped with a fuel
cock: Turn the fuel cock lever to
the off position.5. For vehicles with a carburetor: To
prevent fuel deposits from build-
ing up, drain the fuel in the carbu-
retor float chamber into a clean
container. Retighten the drain bolt
and pour the fuel back into the fuel
tank.
6. Use a quality engine fogging oil
according to product instructions
to protect internal engine compo-
nents from corrosion. If engine
fogging oil is not available, per-
form the following steps for each
cylinder:
a. Remove the spark plug cap
and spark plug.
b. Pour a teaspoonful of engine
oil into the spark plug bore.
c. Install the spark plug cap onto
the spark plug, and then place
the spark plug on the cylinder
head so that the electrodes are
grounded. (This will limit spark-
ing during the next step.)
d. Turn the engine over several
times with the starter. (This will
coat the cylinder wall with oil.)
WARNING! To prevent dam-
age or injury from sparking,
make sure to ground the
spark plug electrodes while
turning the engine over.
[EWA10952]
e. Remove the spark plug cap
from the spark plug, and then
install the spark plug and the
spark plug cap.
7. Lubricate all control cables, piv-
ots, levers and pedals, as well as
the sidestand and centerstand (if
equipped).
UB6GE0E0.book Page 4 Wednesday, August 28, 2019 11:11 AM

Specifications
8-1
8
Dimensions:
Overall length:
1960 mm (77.2 in)
Overall width:
800 mm (31.5 in)
Overall height:
1065 mm (41.9 in)
Seat height:
810 mm (31.9 in)
Wheelbase:
1325 mm (52.2 in)
Ground clearance:
160 mm (6.30 in)
Minimum turning radius:
2.9 m (9.51 ft)
Weight:
Curb weight:
140 kg (309 lb)
Engine:
Combustion cycle:
4-stroke
Cooling system:
Liquid cooled
Valve train:
SOHC
Number of cylinders:
Single cylinder
Displacement:
124 cm³
Bore × stroke:
52.0 × 58.6 mm (2.05 × 2.31 in)
Starting system:
Electric starter
Engine oil:
Recommended brand:
SAE viscosity grades:
10W-40
Recommended engine oil grade:
API service SG type or higher, JASO
standard MA
Engine oil quantity:
Oil change:
0.85 L (0.90 US qt, 0.75 Imp.qt)
With oil filter removal:
0.95 L (1.00 US qt, 0.84 Imp.qt)
Coolant quantity:
Coolant reservoir (up to the maximum level
mark):
0.15 L (0.16 US qt, 0.13 Imp.qt)
Radiator (including all routes):
0.49 L (0.52 US qt, 0.43 Imp.qt)
Fuel:
Recommended fuel:
Unleaded gasoline (E10 acceptable)
Octane number (RON):
95
Fuel tank capacity:
10 L (2.6 US gal, 2.2 Imp.gal)
Fuel reserve amount:
3.0 L (0.79 US gal, 0.66 Imp.gal)
Fuel injection:
Throttle body:
ID mark:
B5G1 00
Drivetrain:
Gear ratio:
1st:
2.833 (34/12)
2nd:
1.875 (30/16)
3rd:
1.364 (30/22)
4th:
1.143 (24/21)
5th:
0.957 (22/23)
6th:
0.840 (21/25)
Front tire:
Type:
Tubeless
Size:
100/80-17M/C 52S
Manufacturer/model:
MICHELIN PILOT STREET
Rear tire:
Type:
Tubeless
Size:
140/70-17M/C 66S
Manufacturer/model:
MICHELIN PILOT STREET
Loading:
Maximum load:
180 kg (397 lb)
UB6GE0E0.book Page 1 Wednesday, August 28, 2019 11:11 AM

10-1
10
Index
A
ABS ....................................................... 3-15
ABS warning light ................................... 3-3
Air filter element and check hose,
replacing and cleaning ....................... 6-13
B
Battery .................................................. 6-30
Brake and clutch levers, checking and
lubricating ........................................... 6-27
Brake and shift pedals, checking and
lubricating ........................................... 6-26
Brake fluid, changing ............................ 6-23
Brake fluid level, checking .................... 6-22
Brake lever ............................................ 3-14
Brake light switches.............................. 6-20
Brake pedal........................................... 3-14
Brake pedal free play, adjusting ........... 6-20
C
Cables, checking and lubricating ......... 6-25
Care ........................................................ 7-1
Catalytic converter ................................ 3-18
Clutch lever ........................................... 3-13
Clutch lever free play, adjusting ........... 6-18
Coolant ................................................. 6-11
Coolant temperature warning light ......... 3-2
Cowlings, removing and installing .......... 6-7
D
Data recording, vehicle ........................... 9-3
Diagnostic connectors ............................ 9-2
Dimmer switch ...................................... 3-12
Drive chain, cleaning and lubricating .... 6-25
Drive chain slack................................... 6-23
E
Engine break-in....................................... 5-1
Engine idling speed .............................. 6-13
Engine oil and oil filter element ............... 6-8
Engine overheating ............................... 6-37
Engine serial number .............................. 9-1
Engine trouble warning light ................... 3-3
F
Front and rear brake pads, checking.... 6-21
Front brake lever free play, checking ... 6-19
Front fork, checking .............................. 6-28
Fuel ....................................................... 3-16
Fuel consumption, tips for reducing ....... 5-5
Fuel tank cap ........................................ 3-16
Fuel tank overflow hose ........................ 3-18
Fuses, replacing.................................... 6-31
H
Handlebar switches .............................. 3-12Helmet holder ....................................... 3-20
High beam indicator light ....................... 3-2
Horn switch .......................................... 3-12
I
Identification numbers ............................ 9-1
Ignition circuit cut-off system............... 3-21
Indicator lights and warning lights ......... 3-2
L
License plate light bulb, replacing........ 6-34
M
Main switch/steering lock....................... 3-1
Maintenance and lubrication, periodic ... 6-4
Maintenance, emission control
system.................................................. 6-3
Matte color, caution ............................... 7-1
Model label ............................................. 9-1
Multi-function meter unit ........................ 3-4
N
Neutral indicator light ............................. 3-2
P
Parking ................................................... 5-6
Part locations ......................................... 2-1
Pass switch .......................................... 3-12
S
Safety information .................................. 1-1
Seat ...................................................... 3-19
Shifting ................................................... 5-4
Shift light ................................................ 3-3
Shift pedal ............................................ 3-13
Sidestand ............................................. 3-20
Sidestand, checking and lubricating .... 6-27
Spark plug, checking ............................. 6-7
Specifications ......................................... 8-1
Start/Engine stop switch ...................... 3-12
Starting the engine ................................. 5-2
Steering, checking................................ 6-29
Storage ................................................... 7-4
Supporting the motorcycle................... 6-34
Swingarm pivots, lubricating ................ 6-28
T
Tail/brake light ...................................... 6-33
Throttle grip and cable, checking and
lubricating .......................................... 6-26
Throttle grip free play, adjusting........... 6-14
Tires ...................................................... 6-15
Tool kit.................................................... 6-2
Troubleshooting ................................... 6-35
Troubleshooting chart .......................... 6-36
Turn signal indicator light ....................... 3-2
Turn signal light bulb, replacing ........... 6-33
UB6GE0E0.book Page 1 Wednesday, August 28, 2019 11:11 AM