The big question is it being fouled with too much fuel or is it an excess of oil?
Excess fuel would initially cause dry soot to form on the insulator until the build-up becomes so severe the carbon begins to short out the spark and then plug wetting will occur. If there is a large amount of excess fuel plug wetting will be almost immediate but this will be obvious due to the inevitable bad running.
If removed it will tend to dry in the free air.
An excess of oil will start to wet the plug almost immediately but the plug won't dry in free air.
Possible causes of excess fuel: leaky carb float valve, carb fuel level too high, mixture maladjusted, blocked air filter...
Possible causes of excess oil: oil level too high, piston rings, valve guides, too much oil in 2-stroke mix, faulty crankcase breather...
A further possibility is the wrong heat grade of spark plug.
826 views
Usually answered in minutes!
×