2004 Official factory service manual for Yamaha YFZ450S ATV Quad., Page 347Get this manual
OVERHEATINGFAULTY BRAKE SHOCK ABSORBER MALFUNCTION EBS00547
TRBL SHTG
OVERHEATING
OVERHEATING Ignition system Improper spark plug gap Improper spark plug heat range Faulty C.D.Iunit Fuel system Improper carburetor main jet (improper setting) Improper fuel level Clogged air filter element Compression system Heavy carbon deposit Engine oil Improper oil level Improper oil viscosity Inferior oil quality Brake Brake drag Cooling system Low coolant level Clogged or damaged radiator Damaged or faulty water pump Faulty fan motor Faulty thermo switch