How do you clean your slant six plugs, or do you even clean them at all?

slantsixdan said
Five of your plugs don't look fouled to me—not at all. They look fantastic; they speak of damn-near-perfect fuel mixture and excellent oil control. The uppermost plug is slightly dirtier, but still has trouble meeting any real definition of "fouled". There's no crusty, gummy, or flaky buildup, and nothing bridging the gap.

If the engine idled a lot better with new plugs, I'd say leave 'em in awhile and see how it goes. You should be able to get at least 20k miles out of a set of good-quality plugs—one of the advantages of today's much cleaner gasoline versus the dirty gunk that was available when these cars were new.

Also quit buying "tools" from Harbor Freight—it's easier and more efficient to just set a pile of cash on the street and light it on fire.

Also, back in the "good old days" when service stations had sandblaster-type spark plug cleaners, a whole hell of a lot of sand stayed in the crevices of the spark plug, and got released directly into the engine after the plugs were reinstalled.

Thanks, Dan. Last time I tuned the motor, I set the idle speed by guessing since I didn't have a tachometer. I then set the idle mixture by "feel", trying to get the smoothest idle with the vacuum advance line removed and plugged as the shop manual recommends. That, along with the new NGK plugs, really made her run well. Later on, I finally got an old school dial type tachometer and checked the idle speed that I set previously. It was at 725 RPM. The shop manual recommends 750, so I'm a good guesser I suppose. As for cleaning the plugs, yeah I scrupulously clean out even the tiniest bit of grit from the inner electrode after I clean them. I'm certain that not a single bit of blasting material or anything else gets introduced into my cylinders. I use a really sharp narrow tipped X-Acto knife to do this. Finally, your point about Harbor Freight is well taken. I returned the plug cleaner and the abrasive that I bought there the next day.