The faults behind exhaust backfires — rich mixture, carburettor settings, valve clearance and spark lead order — and how to fix them.
Bangs from the silencer usually point to an engine problem related to ignition or valve timing. MSG Equipment explains that an overly rich mixture cannot burn completely in the cylinder, passes into the exhaust with the gases and ignites there, causing the pops.
- Carburettor faults: check its settings and the air filter and adjust the fuel supply if needed.
- Incorrect valve clearance: have the cylinder head valves inspected and adjusted.
- Mixed-up spark plug leads: check the order, especially after replacing plugs.
Addressing the problem early helps prevent more serious engine damage.