Hello I have 96 honda 400 TRX400FW im having issues with the muffler rattling...must be a baffle? My cooling fan not kicking on when it shiould be...and my oil temp light comming on at random times. When plowing snow when there is a large load on motor it looses power and the motor itself gets quiet. Can someone help me out here with some suggestiongs.

 

also how do i determine if the motor oil is being circulated??? oil pump? Help