Yamaha RAPTOR YFM660R, Owner'S Manual, Page: 394 / 432

8-129
EBU00724
Troubleshooting chart
Starting problems or poor engine performance
1. Fuel
Check if there is fuel
in the fuel tank.
There is fuel.
Turn the fuel cock
lever to “OFF”.
No fuel.
Fuel cock is
clogged.
Clean the
fuel cock.
Some fuel.
Turn the fuel cock
lever to “RES”.
Restart the engine.
No fuel.
Supply fuel.
2. Compression
Use the electric
starter to see if
there is compression.
There is compression.
Compression normal.
No compression.
Ask a Yamaha dealer to
inspect.
3. Ignition
Remove the
spark plug and
check the electrodes.
Wet Wipe clean with dry cloth.
Dry
Attach spark plug cap and
ground to chassis.
Use the
electric starter.
Spark is good.
Ignition system is
normal.
Spark is weak.
Adjust the spark plug gap
or replace the spark plug.
No spark.
Ask a Yamaha dealer to
inspect.
4. Battery
Use the electric starter.
Engine turns over
quickly.
Battery is good.
Engine turns over
slowly. Check the battery lead connections,
and charge the battery if necessary.
Check the
fuel flow.
Turn the fuel cock
lever to “ON”.
Remove the fuel hose
from the fuel cock.
U5LP64.book Page 129 Thursday, April 1, 2004 4:53 PM