I have a 15 hp Gamefisher mod255.581506. I believe its a 1993 year model. I got it in New condition from an estate sale, but no manual. Can some one tell me the proper spark plug size. I replaced them last year with what was in it (can,t remember the size) but fished all winter with it and they are fouling out. It seems to soon for that so I am questioning the size. Thanks in advance for any and all help.
