2005 Polaris Sportsman 700/800 EFI Service Manual, Page 114Get this manual
TROUBLESHOOTING, CONT
Piston FailureScoring
S Lack of lubrication Dirt entering engine through cracks in air filter or ducts Engine oil dirty or contaminated
Air leaks in intake Lean condition
COOLING SYSTEM TROUBLESHOOTING
Overheating
S Low coolant level Air in cooling system Wrong typemix of coolant Faulty pressure cap or system leaks Restricted system (mud or debris in radiator fins causing restriction to air flow, passages blocked in radiator, lines, pump, or water jacket, accident damage) Lean mixture (restricted jets, vents, fuel pump or fuel valve) Fuel pump output weak Electrical malfunction Water pump failure Loose impeller Thermistor failure Cooling fan inoperative or turning too slowly (perform current draw test) Ignition timing misadjusted Low oil level Spark plug incorrect heat range Faulty hot light circuit Thermostat stuck closed or not opening completely
Excessive Smoke and Carbon Buildup
S Excessive piston-to-cylinder clearance Wet sumping Worn rings, piston, or cylinder Worn valve guides or seals Restricted breather Air filter dirty or contaminated