Carbon build up

Will you burn away carbon build on spark plug and piston?

Examole you install new spark plugd, but the jet is to large so you have some carbon build up the plugs. If you can install correct jets and drive 2-3 hours will the plug then show the truth? Or must you always clean or install new plugs?


Thank you.

To get an accurate reading, new plugs are needed. Yes, some carbon may burn off, but that is not really what we are looking for. The real indication is the color of the ceramic insulator that surrounds the center electrode. Its color is affected by the temperature in that combustion chamber, which is largely determined by the fuel mixture. Once the ceramic is discolored, I am not sure it can be significantly changed.

Depends on how far off you are. If you are super rich or super lean, the plugs will show changes in relatively short time. But when you get close to having correct jetting, the changes take a long time.

The main problem is, you can be lean in some throttle positions and rich in others, so the overall plug reading doesn't tell you enough details. You have to use other methods to determine correct jetting at all positions.