Spark plugs that haven't been changed for a long time can become one with the cylinder head. Fortunately, it's possible to repair damaged threads instead of scrapping the head. (Photograph by Chris ...

Few things disturb us more than the bewilderment of a broken bolt or seized pipe plug in a casting. You’re at a loss for how to get the darned thing out. This is when you have to slow down and come up ...

The space, or gap, between the center and side electrodes needs to be an exact distance across; otherwise, your plugs don't fire efficiently. Adjusting the distance between the two electrodesis called ...

My question is about spark plug reach. I recently removed my intake, and while looking at one valve that was near max lift, I could see the electrode was at least 1/8 inch in the threaded hole. I ...