Polaris RZR XP Service Manual page 424

DIAGNOSTIC
• Lack of lubrication
• Excessive piston-to-cylinder
clearance
• Wet sumping
• Cylinder head gasket leak
• No valve clearance (cam wear)
• Valve not seating properly (bent or
carbon accumulated on sealing
surface)
• Ignition system faulty:
– Spark plug cap cracked /
broken
– Ignition coil faulty
– Ignition or kill switch circuit
faulty
– Poor connections in ignition
system
– Ignition timing incorrect
– Sheared flywheel key
10.14
Piston Failure - Scoring
• Dirt entering engine through
cracks in air filter or ducts
Excessive Smoke and Carbon Buildup
• Worn rings, piston, or cylinder
• Worn valve guides or seals
Low Compression
• Cylinder or piston worn
• Bent valve or stuck valve
Backfiring
• Intake system air leaks
• Fouled spark plug or incorrect plug
or plug gap
• Engine oil dirty or contaminated
• Restricted breather
• Air filter dirty or contaminated
• Piston rings worn, leaking, broken,
or sticking
• Valve spring broken or weak
• Exhaust system air leaks
• Valve sticking
9929419 R02 - 2018-2019 RZR XP / XP 4 Turbo S Service Manual
© Copyright Polaris Industries Inc.