Yamaha Rhino YXR66FAV 2006 Owner's Manual page 375

Engine overheating
Wait until the Check the coolant level in the
engine has cooled. coolant reserver and/or radiator.
NOTE:
_
If it is difficult to get the recommended coolant, tap water can be temporarily used, provided that it is
changed to the recommended coolant as soon as possible.
_
WARNING
Wait for the engine and radiator to cool before removing the radiator cap. You could be burned by
hot fluid and steam blown out under pressure. Always put a thick rag over the cap when opening.
Allow any remaining pressure to escape before completely removing the cap.
Level is low, check the
cooling system for leakage.
Restart the engine. If the engine overheats again, ask a
Level is OK.
Yamaha dealer to inspect and/or repair the cooling system.
8-136
Ask a Yamaha dealer to inspect
Leakage.
and repair the cooling system.
No
Add coolant. (See NOTE.)
leakage.