Polaris Sportsman 9921483 Owner's Manual page 189

Troubleshooting
Engine Backfires
Possible Cause
Weak spark from spark plugs
Incorrect spark plug gap or heat range
Old or non-recommended fuel
Incorrectly installed spark plug wires
Incorrect ignition timing
Mechanical failure
Exhaust system leak
186
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
See your Polaris dealer