Champion 3X Spark Plug

[Fullraceflathead]

If you disassemble them you will find that a scotch Brite pad and brake cleaner are excellent to clean them with.

[fried okra]

Anyone use Berryman B-12 fuel injection cleaner to soak plug tips in to clean them?

[Kurt in NJ]

I just turn down the GAV , burn them white with lean mixture, got 2 sets of 3x in the trash because fouling with carbon, 20 miles and they were white and clean, C4 take a hard run to clean.
If fouling to the point of no spark jumping gap give a additional spark gap at the cap to force the spark to jump.
First and last pictures are C4,, middle picture are the way my 3x burn with ethonal laced gas.
I think many play with heat range to cover mixture problems.
the C4 cleaned that much in a 5 mile run.

[woofa.express]

I well remember when avgas was high in tetraethyl lead and sparkplugs which would build between the electrode insulation and plug casing. We cleaned them at each 100 hourly service using a plug cleaner which blasted sand. This method was not suitable for plugs with platinum electrodes as it eroded them rather rapidly.
For these plugs we took a hacksaw blade, a worn one, and ground down one edge about 2 inches which then fitted well between the 2 electrodes and we physically levered out the lead build-up. No erosion on the electrodes nor insulator. And no change in the gap. Maybe that may help?