us Marine 50 hp help

[fishermanbtr3]

Not sure what year or anything on this motor. Needs plugs but the plug is flat. Not sure what to go with

 

[Frank Acampora]

It is called a surface gap plug and is designed to run very cold The center electrode is completely encapsulated by the plug shell and threads and id kept cool by the head and water jacket.

They do tend to foul easily but If cleaned regularly, they can last the life of the engine. The plug is only "bad" if the center electrode is worn down below the surface of the porcelain insulator.

To answer your question: Good plugs to use would be Champion L20V, UL18v, NGK BUHX or BUHW or Mercury Champion L76V

 

[CJ River Rider]

Frank, what would you suggest to use to clean them, scotch-brite pads or something else?

 

[Frank Acampora]

I personally cut a green Skotchbrite pad into about 1 inch squares (Tough on the scissor edges though). Then I use the corner of the small pad to clean--four corners per pad. When they gunk up with carbon and oil I just throw them away. I just push it into the gap with my fingernail and rotate until the plug meets my satisfaction. . It gets out all the crud but will leave a stain on the porcelain.

 

[CJ River Rider]

Thanks Frank.