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 ...

A spark plug thread chaser isn't always the answer, but it can make a big difference when you're installing fresh new plugs.

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 ...