Troubleshooting Chart - Yamaha Big Bear YFM400R 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 the plug and
check the electrodes.
4. Battery
Use the electric starter.
Turn the fuel
There is fuel.
cock to "OFF".
Turn the fuel
Some fuel.
cock to "RES".
No fuel.
Supply fuel.
There is compression.
Compression normal.
No compression.
Ask a Yamaha dealer to inspect.
Wipe clean with
Wet
dry cloth.
Attach plug cap and
Dry
ground to chassis.
Engine turns over
Battery good.
quickly.
Engine turns over Recharge, check
slowly. connections.
Turn the fuel
cock to "ON".
Check fuel
Remove the fuel pipe.
flow.
Restart engine.
Use the
electric starter.
Ask a Yamaha dealer to inspect.
8-40
No fuel.
Ignition system
Spark good.
normal.
Spark weak.
Adjust plug gap
No spark.
or replace plug.
Fuel cock
clogged.
Clean fuel
cock.