2008 Polaris Sportsman 500 EFI/X2/Touring/500 H.O. Service Manual, Page 114Get this manual
ENGINE Engine Has Low Power Spark plug fouled Cylinder, piston, ring, or valve wear or damage (check compression) PVT not operating properly Restricted exhaust muffler Carburetor damaged vacuum slide stickingdiaphragm Ignition system faulty: Spark plug cap crackedbroken Ignition coil faulty Ignition or kill switch circuit faulty Ignition timing incorrect Sheared flywheel key Poor connections in ignition system System wiring wet Valve sticking Air leaks in intake Lean condition
Dirty carburetor Piston FailureScoring Lack of lubrication Dirt entering engine through cracks in air filter or ducts Engine oil dirty or contaminated Excessive Smoke and Carbon Buildup Excessive piston-to-cylinder clearance Wet sumping Worn rings, piston, or cylinder Worn valve guides or seals Restricted breather Air filter dirty or contaminated Low Compression Decompressor stuck Cylinder head gasket leak No valve clearance or incorrectly adjusted Cylinder or piston worn Piston rings worn, leaking, broken, or sticking Bent valve or stuck valve Valve spring broken or weak Valve not seating properly (bent or carbon accumulated on sealing surface) Rocker arm sticking Backfiring ETC or speed limiter system malfunction Fouled spark plug or incorrect plug or plug gap Carburetion faultylean condition Exhaust system air leaks