Typical causes for carbon buildup on the plug would be:
* Dirty air filter
* Carburetor running too rich
* Spark plug running too cold
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The fix for the first item is pretty easy; clean or replace the air filter.
If the carburetor is running too rich, you may be able to adjust the mix, or it may be time for a rebuild; small engine carburetors are usually fairly inexpensive and easy to rebuild.
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For the third item on the list, it's possible the plug was replaced with one that isn't quite right for your engine, or it could be as simple as replacing it with a new, correct one and/or cleaning and setting the proper plug gap.
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For the third item on the list, it's possible the plug was replaced with one that isn't quite right for your engine, or it could be as simple as replacing it with a new, correct one and/or cleaning and setting the proper plug gap. Getting further into it, it's also possible the plug wire is introducing too much resistance and lowering the current needed for spark, or the magneto could be having problems and not generating enough current, but save messing with that for last after everything else has been checked.
Typical causes for carbon buildup on the plug would be:
* Dirty air filter
* Carburetor running too rich
* Spark plug running too cold
The fix for the first item is pretty easy; clean or replace the air filter.
If the carburetor is running too rich, you may be able to adjust the mix, or it may be time for a rebuild; small engine carburetors are usually fairly inexpensive and easy to rebuild.
For the third item on the list, it's possible the plug was replaced with one that isn't quite right for your engine, or it could be as simple as replacing it with a new, correct one and/or cleaning and setting the proper plug gap.