Polaris Predator 9920779 Owner's Manual page 171

TROUBLESHOOTING
Engine Pings or Knocks
Possible Cause
Poor quality or low octane fuel
Incorrect ignition timing
Incorrect spark plug gap or heat range
Engine Backfires
Possible Cause
Weak, fouled or defective spark plug
Incorrect spark plug gap or heat range
Old, poor or non-recommended fuel
Incorrectly installed spark plug wire
Incorrect ignition timing
Mechanical failure
168
Solution
Replace with recommended fuel
See your Polaris dealer
Set gap to specs or replace plugs
Solution
Inspect, clean and/or replace spark plugs
Set gap to specs or replace plugs
Replace with new fuel
See your Polaris dealer
See your Polaris dealer
See your Polaris dealer