The requirement to gap spark plugs might not be as common as it once was, but it's still an important bit of maintenance on ...

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 ...

In olden times, part of the ritual of changing your engine's spark plugs was making sure that the gap was set correctly for optimum performance. That is, the distance between the spark plug's center ...