What are the causes of backfiring in motorcycle exhaust pipes?
2 Answers
The causes of backfiring in motorcycle exhaust pipes are: 1. Overly rich air-fuel mixture; 2. Incorrect ignition timing; 3. Incorrect valve timing; 4. Mechanical failures such as broken piston rings or cylinder damage. The reasons for difficulty starting a motorcycle when cold are: 1. High viscosity of engine oil; 2. Dirty air filter needing cleaning or replacement; 3. Incorrect starting method; 4. Improper carburetor adjustment; 5. Decreased engine performance. Methods to start a motorcycle with a dead battery are: 1. Use the kick starter to start the motorcycle; 2. Engage third gear with the clutch, push the motorcycle to maximum speed, then release the clutch to start the engine; 3. Charge the battery or replace it before starting.
I've been riding motorcycles for over 20 years, and backfiring in the exhaust is quite common. It mainly happens because unburned fuel enters the exhaust pipe and ignites. If the air-fuel mixture is too rich, too much fuel enters the engine, which can't handle it, and the excess fuel gets expelled, igniting when it heats up. Late ignition timing has a similar effect, where the spark plug doesn't fire in time. Also, if the spark plug is old, unstable, or dirty, some fuel may escape unburned. If there's an exhaust leak, air can get sucked in and help ignite the fuel, making things worse. It's not just annoying noise—it can crack the exhaust pipe or even damage the engine. After experiencing this a few times, I now regularly check the spark plugs and adjust the air-fuel mixture. Small issues left unfixed can turn into big problems.
