2. Inspect the spark plugs. Worn spark plugs can cause misfires, which can lead to backfiring. Remove the spark plugs and inspect them for wear. Replace them if necessary.
3. Adjust the fuel mixture. A rich fuel mixture can cause backfiring. Use a carburetion analyzer to check the fuel mixture and adjust it according to the manufacturer's specifications.
4. Check the exhaust system. A leak in the exhaust system can cause backfiring. Use a flashlight to inspect the exhaust system for any leaks and repair them if necessary.
5. Have the engine tuned up. If the above steps do not resolve the problem, have the engine tuned up by a qualified mechanic. This may include adjusting the timing, setting the valve clearances, and cleaning the carburetor.
