2021 YAMAHA MT-125 periodic maintenance

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)]

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

Periodic maintenance an d a djustment
6-1
6
EAU17246
Periodic inspection, adjustment, and
lubrication will keep your vehicle in the
safest and most efficient condition
possible. Safety is an obligation of the
vehicle owner/operator. The most im-
portant points of vehicle inspection,
adjustment, and lubrication are ex-
plained on the following pages.
The intervals given in the periodic
maintenance charts should be simply
considered as a general guide under
normal riding conditions. However, de-
pending on the weather, terrain, geo-
graphical location, and individual use,
the maintenance intervals may need to
be shortened.
WARNING
EWA10322
Failure to properly maintain the vehi-
cle or performin g maintenance ac-
tivities incorrectly may increase
your risk of injury or death during
service or while usin g the vehicle. If
you are not familiar with vehicle ser-
vice, have a Yamaha d ealer perform
service.
WARNING
EWA15123
Turn off the en gine when performin g
maintenance unless otherwise
specified .
 A runnin g en gine has movin g
parts that can catch on b ody
parts or clothin g an d electrical
parts that can cause shocks or
fires.
 Runnin g the eng ine while ser-
vicin g can lead to eye injury,
b urns, fire, or car bon monoxi de
poisonin g – possi bly lea din g to
d eath. See pag e 1-3 for more in-
formation a bout car bon monox-
i d e.
WARNING
EWA15461
Brake discs, calipers, drums, an d
linin gs can b ecome very hot during
use. To avoi d possi ble burns, let
b rake components cool before
touching them.
EAU17303
Emission controls not only function to
ensure cleaner air, but are also vital to
proper engine operation and maximum
performance. In the following periodic
maintenance charts, the services relat-
ed to emissions control are grouped
separately. These services require
specialized data, knowledge, and
equipment. Maintenance, replace-
ment, or repair of the emission control
devices and systems may be per-
formed by any repair establishment or
individual that is certified (if applicable).
Yamaha dealers are trained and
equipped to perform these particular
services.
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Periodic maintenance an d a djustment
6-2
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EAU85230
Tool kitThe tool kit is in the location shown.
The information included in this manual
and the tools provided in the tool kit are
intended to assist you in the perfor-
mance of preventive maintenance and
minor repairs. However, a torque
wrench and other tools are necessary
to perform certain maintenance work
correctly.TIPIf you do not have the tools or experi-
ence required for a particular job, have
your Yamaha dealer perform it for you.1. Tool kit
1
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Periodic maintenance an d a djustment
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EAU71021
TIP The annual checks must be performe d every year, except if a distance- based maintenance is performe d in-
stea d.
 From 30000 km (17500 mi), repeat the maintenance intervals starting from 6000 km (3500 mi).
 Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and tech-
nical skills.
EAU71041
Perio dic maintenance chart for the emission control systemNO. ITEM CHECK OR MAINTENANCE JOB ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)
1 *Fuel line • Check fuel hoses for cracks or
damage.
• Replace if necessary. √√√√√
2 *Spark plu g • Check condition.
• Adjust gap and clean.
√√
•Replace. √√
3 *Valve clearance • Check and adjust. √√√√
4 *Fuel injection • Check and adjust engine idle
speed. √√√√√√
5 *Exhaust system • Check for leakage.
• Tighten if necessary.
• Replace gasket if necessary. √√√√√
6 *Evaporative emis-
sion control system • Check control system for dam-
age.
• Replace if necessary. √√
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6
EAU71342
General maintenance an d lu brication chartNO. ITEM CHECK OR MAINTENANCE JOB ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)
1 *Dia
gnostic system
check • Perform dynamic inspection us-
ing Yamaha diagnostic tool.
• Check the error codes. √√√√√√
2 *Air filter element • Replace. √√
3 Air filter case check
hose • Clean.
√√√√√
4Clutch • Check operation.
•Adjust.
√√√√√
5 *Front brake • Check operation, fluid level, and
for fluid leakage.
• Replace brake pads if necessary. √√√√√√
6 *Rear brake • Check operation, fluid level, and
for fluid leakage.
• Replace brake pads if necessary. √√√√√√
7 *Brake hoses • Check for cracks or damage.
√√√√√
• Replace. Every 4 years
8 *Brake flui d • Change. Every 2 years
9 *Wheels • Check runout and for damage.
• Replace if necessary. √√√√
10 *Tires • Check tread depth and for dam-
age.
• Replace if necessary.
• Check air pressure.
• Correct if necessary. √√√√√
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Periodic maintenance an d a djustment
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11 *Wheel bearin gs • Check bearing for looseness or
damage. √√√√
12 *Swin
garm pivot
b earin gs • Check operation and for exces-
sive play. √√√√
• Lubricate with lithium-soap- based grease. Every 24000 km (14000 mi)
13 Drive chain • Check chain slack, alignment and
condition.
• Adjust and lubricate chain with a special O-ring chain lubricant
thoroughly. Every 1000 km (600 mi) and after washing the motorcycle, riding in the rain or
riding in wet areas
14 *Steerin g b earin gs • Check bearing assemblies for
looseness. √√√√
• Moderately repack with lithium- soap-based grease. √
15 *Chassis fasteners • Make sure that all nuts, bolts and
screws are properly tightened. √√√√√
16 Brake lever pivot
shaft
• Lubricate with silicone grease.
√√√√√
17 Brake ped
al pivot
shaft • Lubricate with lithium-soap-
based grease. √√√√√
18 Clutch lever pivot
shaft • Lubricate with lithium-soap-
based grease. √√√√√
19 Shift pe
dal pivot
shaft • Lubricate with lithium-soap-
based grease. √√√√√
NO. ITEM CHECK OR MAINTENANCE JOB
ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)
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6
20 Si destan d • Check operation.
• Lubricate with lithium-soap-
based grease. √√√√√
21 *Sidestan d switch • Check operation and replace if
necessary. √√√√√√
22 *Front fork • Check operation and for oil leak-
age.
• Replace if necessary. √√√√
23 *Shock a
bsor ber as-
sem bly • Check operation and for oil leak-
age.
• Replace if necessary. √√√√
24 *Rear suspension re-
lay arm an
d con-
nectin g arm
pivotin g points • Check operation.
√√√√
• Lubricate with lithium-soap- based grease. √√
25 En gine oil • Change (warm engine before
draining).
• Check oil level and vehicle for oil leakage. At the initial interval and
every 3000 km (1800 mi) thereafter. √
26 En
gine oil filter ele-
ment • Replace.
√√√√√
27 *Coolin g system • Check coolant level and vehicle
for coolant leakage. √√√√√
• Change. Every 3 years
28 *Front an
d rear
b rake switches • Check operation.
√√√√√√
29 *Movin
g parts an d
cab les • Lubricate.
√√
√√√
NO. ITEM CHECK OR MAINTENANCE JOB
ODOMETER READING
ANNUAL
CHECK
1000 km
(600 mi) 6000 km
(3500 mi) 12000 km
(7000 mi) 18000 km
(10500 mi) 24000 km
(14000 mi)
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