plug fouling, issues

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
hi, Im wondering if an auto spark plug can burn carbon off once it is all carboned up if the changes are made to the engine to give the proper air fuel mix. Can plugs be cleaned of carbon and can plugs be bead blasted to clean or does it ruin the plug. What would be a way to clean the plug? Or does it go in the dumpster? Also can a plug show a spark outside of the engine but not spark under pressure of the cylinder?
thanks jim


REMOVE PLUGS AND HEAT THE GROUND ELECTODE RED WITH A PROPANE TORCH,
propanetorch.gif

before you re-install them,
this will burn off a significant amount out of fouling, in many cases thats all thats needed to get them firing correctly, they will self clean once they are in a running engine, this works exceptionally well in smaller engines you foul plugs on like chain saws, lawn mowers, pressure washers that don't get run frequently.
gap the plugs at .043-.045 in almost all cases







 
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That’s a good point. Its quite different to test a sparkplug outside an engine when the sparkplug gap resistance is at a normal atmospheric pressure of about 16 psi as oppossed to almost 1300 psi inside an engin’s cylinder. As pressure increases so should the voltage. There is an inexpensive tool that allows you to see the spark color and intensit.
 
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