Page 42 - Manual_Polaris_RZR_ProXP-20-21

GENERAL INFORMATION

ENGINE HAS LOW POWER

• Spark plug fouled • PVT not operating properly • Restricted exhaust muffler
• Cylinder, piston, ring, or valve • Cam worn excessively • Low fuel pressure
wear or damage (check
compression)
• Poor fuel quality

PISTON FAILURE - SCORING

• Lack of lubrication • Dirt entering engine through • Engine oil dirty or contaminated
cracks in air filter or ducts
• Improper air filter maintenance

EXCESSIVE SMOKE (BLUE / BLACK) AND CARBON BUILDUP

• Excessive piston-to-cylinder • Worn rings, piston, or cylinder • Restricted breather
clearance
• Worn valve guides or seals • Air filter dirty or contaminated
• Wet sumping

LOW COMPRESSION

• Cylinder head gasket leak • Cylinder or piston worn • Piston rings worn, leaking, broken,
or sticking
• No valve clearance (cam wear) • Bent valve or stuck valve
• Valve spring broken or weak
• Valve not seating properly (bent or
carbon accumulated on sealing
surface)

BACKFIRING

• Ignition system faulty: • Intake system air leaks • Exhaust system air leaks
– Spark plug cap cracked / • Fouled spark plug or incorrect plug • Valve sticking
broken or plug gap
– Ignition coil faulty • Throttle Body (installed incorrect /
– Ignition or kill switch circuit • Low fuel pressure electrical concern / failed)
faulty
– Poor connections in ignition • Poor fuel quality
system
– Ignition timing incorrect
– Sheared flywheel key

1.36 9930583 R01 - 2020-2021 RZR PRO XP / XP 4 Service Manual
© Copyright Polaris Industries Inc.