a poster by the handle of steve is struggling with the name and function of the
plugs on engines used on commercial fishing boats that need to be cleaned by
the crew the night be sailing. he knows they exist and he knows they are not
cleaned as part of the normal engine tear down and rebuild done after each
trip. he knows the crew does in fact clean them, but he just can't remember
what they are called, nor what their function is.

can someone help steve out here? Does someone know the name and/or function of
these required-to-be-cleaned-the-night-before-sailing plugs on the engine? It
seems a couple of other people also have a blank spot as to the name/function
of these plugs and also would like to know.

Thanks in advance.