Where are the spark plugs located on a 2001 Mercury Optimax 225, all I can find on the end of the plug wire is a thin black box, that has the end of a spark plug coming out of it, if that makes sense. But I cannot find the plug at all? I need to change them, because one of them foulded out, please help, I know this is a goofy question, but I have never had problems finding plugs on a boat before, and I am seriously lost on this one.
