Troubleshooting Chart - Yamaha BIGBEAR YFM400NM Owner's Manual

EBU00440

Troubleshooting chart

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 plug and
check electrode.
4. Battery
Use the electric
starter.
Turn the fuel
There is fuel.
cock to "OFF".
Turn the fuel
Some fuel.
cock 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 plug cap and
Dry
ground to chassis.
Engine turns over
Battery good.
quickly.
Engine turns over Check fluid, recharge,
slowly.
check connections.
Remove the Check fuel
fuel pipe. flow.
Restart engine.
Use the
electric starter.
Ask a Yamaha dealer to
inspect.
8-37
No fuel.
Ignition system
Spark good.
normal.
Spark weak.
Adjust plug gap
No spark.
or replace plug.
Fuel cock
clogged.
Clean fuel
cock.