Why does lawnmower spark plug keep fouling?
Carbon collects on the plug electrodes because of incomplete combustion. ... If the carburetor sprays too much fuel into the combustion chamber, the fuel burns cooler. The smoke that results fouls the plug as well as the air filter and the spark arrestor that covers the engine's exhaust port.
Also know, why does my lawn mower spark plug turn black?
A black, feathery carbon deposit on your spark plugs can be an indication of a weak spark or an overly rich fuel mixture. Causes may include a stuck choke, misadjusted or heavy carburetor float, a leaky injector or carburetor needle valve, low coil output or high resistance in your spark plug wires.
In this way, why are my spark plugs Sooty?
Black, dry soot on the electrodes and insulator tip indicates a carbon-fouled plug. This can be caused by a dirty air filter, excessive driving at low speeds, too rich of a fuel/air mixture or idling your vehicle for too long.
How long does a lawn mower spark plug last?
Typically, the consensus among the mechanical engineer community is that a spark plug for a lawn mower will last up to 25 hours of use. Some users simply prefer to replace it every mowing season as a part of their yearly lawn mower maintenance.