What's happening:
* Backfiring: The pops you're hearing are backfires. This means the combustion process is happening out of sync, and the explosion is pushing flames backward through the intake system.
* Flames out the air filter: The flames coming out the air filter are a clear indication of the backfiring issue. This is extremely dangerous and could cause a fire.
Potential Causes:
1. Carburetor Problems:
* Incorrect jetting: The carburetor might be set up incorrectly, leading to an overly rich fuel mixture that's not igniting properly in the cylinder.
* Clogged jets: Dirt or debris can clog the jets in the carburetor, preventing the proper flow of fuel.
* Diaphragm issues: The carburetor's diaphragm, which controls fuel flow, could be worn out or damaged.
2. Ignition Problems:
* Spark plug issues: A fouled, worn, or improperly gapped spark plug can lead to misfiring and backfires.
* Ignition coil malfunction: The ignition coil, responsible for providing the spark, could be failing.
* Timing issues: The timing of the spark plug might be off, causing the combustion to occur at the wrong time.
3. Air Intake Issues:
* Air filter blockage: A dirty or clogged air filter can restrict airflow and cause backfires.
* Loose or damaged intake manifold: A leak in the intake manifold allows air to enter the engine at the wrong time, disrupting the air/fuel mixture.
What You Should Do:
1. Safety First: Stop using the engine immediately. The flames coming out the air filter are a fire hazard.
2. Inspect the Air Filter: Ensure the air filter is clean and not clogged. Replace it if necessary.
3. Check the Spark Plug: Remove the spark plug and inspect it. Make sure it's not fouled, worn, or corroded. If necessary, replace it with a new one of the correct type and gap.
4. Inspect the Carburetor:
* Clean it thoroughly: If you're comfortable doing so, carefully disassemble the carburetor and clean all parts with carburetor cleaner. Pay special attention to the jets.
* Check the diaphragm: Inspect the diaphragm for damage or tears. Replace it if necessary.
* Adjust the jetting: If you have experience with carburetor tuning, you may need to adjust the jetting to get the correct fuel mixture. However, if you're unsure, it's best to seek help from a mechanic.
5. Check the Ignition Coil: Make sure the ignition coil connections are secure and the coil itself doesn't appear damaged.
6. Inspect the Intake Manifold: Check the intake manifold for any leaks or cracks.
Seek Professional Help:
If you're not comfortable working on the engine yourself or if the problem persists after attempting these steps, it's crucial to consult a qualified small engine mechanic. They can properly diagnose and repair the issue.
Important Note: Backfires can be dangerous. Always wear safety goggles and gloves when working on an engine, and be cautious of hot parts.
