2016 YAMAHA MT-125 ignition

Periodic maintenance and adjustment
6-41
6
EAU25872
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur
during operation. Any problem in the
fuel, compression, or ignition systems,
for example, can cause poor starting
and loss of power.
The following troubleshooting charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your motorcycle
require any repair, take it to a Yamaha
dealer, whose skilled technicians have
the necessary tools, experience, and
know-how to service the motorcycle
properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life and
can lead to expensive repair bills.
WARNING
EWA15142
When checking the fuel system, do
not smoke, and make sure there are
no open flames or sparks in the ar-
ea, including pilot lights from water
heaters or furnaces. Gasoline or
gasoline vapors can ignite or ex-
plode, causing severe injury or prop-
erty damage.
UBR3E0E0.book Page 41 Friday, June 19, 2015 1:19 PM

Periodic maintenance and adjustment
6-42
6
EAU68070
Troubleshooting charts
Starting problems or poor engine performance
1. FuelThere is enough fuel.
There is no fuel.Supply fuel.
The engine turns over
quickly.
Operate the electric
starter.
Check the
compression.
The engine turns over
slowly.
Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug.
Check the electrolyte
and battery lead
connections, and
charge the battery if
necessary.
The engine does not
start.
Have a Yamaha
dealer check the
vehicle.
4. BatteryThe battery is good.
3. IgnitionWet
Dry
The engine does not
start.
Check the
compression.
Have a Yamaha
dealer check the
vehicle.The engine does not
start.
Check the battery.
Remove the spark
plug and check
the electrodes.
Check the fuel level
in the fuel tank.
Operate the electric
starter.
Operate the electric
starter.
There is compression.
There is no
compression.Have a Yamaha dealer check the vehicle.
Check the ignition.2. Compression
UBR3E0E0.book Page 42 Friday, June 19, 2015 1:19 PM

Specifications
8-3
8
Wheel travel:
130 mm (5.1 in)
Rear suspension:
Type:
Swingarm (link suspension)
Spring/shock absorber type:
Coil spring/oil damper
Wheel travel:
114 mm (4.5 in)
Electrical system:
System voltage:
12 V
Ignition system:
TCI
Charging system:
AC magneto
Battery:
Model:
12N5.5-4A / YUASA
Voltage, capacity:
12 V, 5.5 Ah
Headlight:
Bulb type:
Halogen bulb
Bulb voltage, wattage × quantity:
Headlight:
12 V, 55.0 W/60.0 W × 1
Brake/tail light:
LED
Front turn signal light:
12 V, 10.0 W × 2
Rear turn signal light:
12 V, 10.0 W × 2
Auxiliary light:
LED
License plate light:
12 V, 5.0 W × 1
Meter lighting:
LED
Neutral indicator light:
LED
High beam indicator light:
LED
Turn signal indicator light:
LED
Fuel level warning light:
LED
Engine trouble warning light:
LEDABS warning light:
LED (MT125-A)
Fuse:
Main fuse:
20.0 A
Headlight fuse:
15.0 A
Signaling system fuse:
7.5 A
Ignition fuse:
7.5 A
Radiator fan motor fuse:
5.0 A
ABS control unit fuse:
10.0 A (MT125-A)
ABS motor fuse:
30.0 A (MT125-A)
ABS solenoid fuse:
20.0 A (MT125-A)
Backup fuse:
10.0 A
UBR3E0E0.book Page 3 Friday, June 19, 2015 1:19 PM

10-1
10
Index
A
ABS (for ABS models) .......................... 3-15
ABS warning light (for ABS models)....... 3-2
Air filter element and check hose,
replacing and cleaning ....................... 6-14
Auxiliary lights ...................................... 6-35
B
Battery .................................................. 6-31
Brake and clutch levers, checking and
lubricating .......................................... 6-27
Brake fluid, changing ........................... 6-24
Brake fluid level, checking ................... 6-23
Brake lever ........................................... 3-14
Brake light switches ............................. 6-21
Brake pedal .......................................... 3-14
Brake pedal, checking and
lubricating .......................................... 6-28
Brake pedal free play, adjusting........... 6-21
C
Cables, checking and lubricating ......... 6-26
Care ........................................................ 7-1
Catalytic converter ............................... 3-18
Clutch lever .......................................... 3-13
Clutch lever free play, adjusting ........... 6-19
Coolant ................................................. 6-12
Cowlings, removing and installing ......... 6-7
D
Dimmer switch ..................................... 3-11
Drive chain, cleaning and lubricating ... 6-26
Drive chain slack .................................. 6-24
E
Engine break-in ...................................... 5-4
Engine idling speed, checking ............. 6-14
Engine oil and oil filter element .............. 6-9
Engine stop switch ............................... 3-12
Engine trouble warning light................... 3-2
F
Front and rear brake pads, checking ... 6-22
Front brake lever free play, checking ... 6-20
Front fork, checking ............................. 6-29
Fuel....................................................... 3-16
Fuel consumption, tips for reducing ...... 5-4
Fuel level warning light ........................... 3-2
Fuel tank cap........................................ 3-16
Fuses, replacing ................................... 6-32
H
Handlebar switches.............................. 3-11
Headlight bulb, replacing ..................... 6-34
High beam indicator light ....................... 3-2
Horn switch .......................................... 3-12
I
Identification numbers ............................ 9-1
Ignition circuit cut-off system ............... 3-20
Indicator lights and warning lights .......... 3-2
Info switch ............................................ 3-12
L
License plate light bulb, replacing ........ 6-37
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 .................................................... 5-5
Part locations .......................................... 2-1
Pass switch........................................... 3-11
R
Rider seat.............................................. 3-18
S
Safety information................................... 1-1
Shifting .................................................... 5-3
Shift pedal............................................. 3-13
Sidestand .............................................. 3-19
Sidestand, checking and lubricating .... 6-28
Spark plug, checking .............................. 6-8
Specifications ......................................... 8-1
Starting the engine.................................. 5-2
Start switch ........................................... 3-12
Steering, checking ................................ 6-30
Storage ................................................... 7-4
Supporting the motorcycle ................... 6-37
Swingarm pivots, lubricating ................ 6-29
T
Tail/brake light ...................................... 6-36
Throttle grip and cable, checking and
lubricating ........................................... 6-27
Throttle grip free play, adjusting ........... 6-15
Tires ...................................................... 6-16
Tool kit .................................................... 6-2
Troubleshooting .................................... 6-41
Troubleshooting charts ......................... 6-42
Turn signal indicator light ....................... 3-2
Turn signal light bulb, replacing............ 6-36
Turn signal switch ................................. 3-12
UBR3E0E0.book Page 1 Friday, June 19, 2015 1:19 PM