Troubleshooting Chart - Yamaha MT-125 Owner's Manual

Periodic maintenance and adjustment

Troubleshooting chart

1. Fuel
Check the fuel level
in the fuel tank.
2. Battery
Operate the electric
starter.
6
3. Ignition
Remove the spark
plug and check
the electrodes.
4. Compression
Try starting the
engine.
There is enough fuel.
There is no fuel.
The engine turns over
quickly.
The engine turns over
slowly.
Wet
Dry
There is compression.
There is no
compression.
6-36
Check the battery.
Supply fuel.
The battery is good.
Check the battery
lead connections,
and charge the
battery if necessary.
Wipe off with a dry
cloth and correct the
spark plug gap, or
replace the spark
plug(s).
Have a Yamaha
dealer check the
vehicle.
The engine does not start.
Have a Yamaha dealer check the vehicle.
Have a Yamaha dealer check the vehicle.
EAU86390
The engine does not
start.
Check the battery.
The engine does not
start.
Check the ignition.
Try starting the
engine.
The engine does not
start.
Check the
compression.