Troubleshooting chart
Starting problems or poor engine performance
1. Fuel
Check if there is fuel
in the fuel tank.
2. Compression
Use the electric
starter to see if
there is compression.
3. Ignition
Remove the
spark plug and
check electrodes.
4. Battery
Use the electric starter.
Turn the fuel cock
There is fuel.
lever to "OFF".
Turn the fuel cock
Some fuel.
lever to "RES".
Supply fuel.
No fuel.
There is compression.
Compression normal.
Ask a Yamaha dealer to
No compression.
inspect.
Wipe clean with dry cloth.
Wet
Attach spark plug cap and
Dry
ground to chassis.
Engine turns over
Battery is good.
quickly.
Engine turns over
Check the connections.
slowly.
Turn the fuel cock
lever to "ON".
Remove the fuel hose
Check the
from the fuel cock.
fuel flow.
Restart the engine.
Use the
electric starter.
8-125
No fuel.
Ignition system is
Spark is good.
normal.
Spark is weak.
Adjust the spark plug gap
No spark.
or replace the spark plug.
Ask a Yamaha dealer to
inspect.
EBU00724
Fuel cock is
clogged.
Clean the
fuel cock.
