How to Deal with a Flooded Spark Plug in a Motorcycle?
2 Answers
Do not use the choke. Instead, fully open the throttle and repeatedly step on the pedal several times to expel the accumulated fuel in the cylinder. If there is excessive fuel, remove the spark plug for cleaning. Generally, there are two scenarios for a flooded spark plug: 1. The air filter and carburetor are too dirty and require cleaning. The carburetor's mixture is too rich or the fuel level is too high, leading to excessive fuel supply that cannot be completely burned and adheres to the spark plug. In this case, the exhaust pipe will emit black smoke when the engine is accelerated. 2. Severe wear of the cylinder, piston, piston rings, or valve oil seals causes oil burning. In this scenario, the exhaust pipe will emit blue smoke. Additionally, adding too much engine oil can also lead to oil burning. After oil burning, carbon deposits will form on the spark plug, causing it to flood.
I've been riding motorcycles for over a decade and have encountered spark plug flooding several times, mostly caused by water ingress during rainy days or carburetor fuel leaks. Handling it isn't too difficult: first turn off the engine, carefully remove the spark plug with a dedicated wrench, and if the electrodes are wet, wipe them dry with a cloth or use compressed air to blow them dry. When out in the wild without tools, I carry spare spark plugs for direct replacement. After cleaning, reinstall and try starting; if it doesn't ignite, it might be severe fuel flooding, requiring a check of whether the carburetor's fuel nozzle is dirty or the sealing ring is damaged. For prevention, I've developed the habit of checking that the air intake isn't blocked before each ride, avoiding water depths beyond the wheel axle, and promptly drying the engine parts after rainy days. Regular maintenance is most effective—I inspect the spark plugs every three months to prevent issues from aging. If flooding recurs, it's best to have a mechanic conduct a comprehensive check-up rather than pushing through to avoid engine damage.
