2004 Polaris Freedom, Virage, Genesis and MSX-140 Service Manual., Page 51Get this manual
MAINTENANCE General TroubleshootingContinued Piston Damage
Symptoms: Hole in piston
Water in carburetors or fuel Lean fuel mixture (see lean condition troubleshooting) Detonation from incorrect ignition timing, poor quality fuel, modified cylinder heads, excessive carbon buildup, etcIncorrect spark plug Overheated engine Flywheel key sheared, keyway damaged, flywheel damage Crankshaft out of index Lean fuel mixture (see lean condition troubleshooting) Detonation from incorrect ignition timing, poor quality fuel, modified cylinder heads, excessive carbon buildup, etcEngine overheating (inspect cooling system) Crankshaft out of index (see engine section) Flywheel key sheared Water in oil Oil pump failure Oil tank vent problem restricted, check valve in backward Pinched or restricted lines Lean fuel mixture (see carburetion) Poor quality fuel Water in fuel Engine overheating Hydrolocked engine (water or fuel) Foreign material in engine Excessive piston to cylinder clearance Foreign material in engine Sharp ports Modified engine Hydrolocked engine (water or fuel)