Re: I need to find out what spark plug for a old evinrude.
I think that engine is the equivalent to the Johnson TD-20 5HP.<br /><br />The Johnson used a J8J, but the Evinrude was rated a bit higher and probably used the J6J.<br /><br />The modern replacements are J8C? and J6C.<br /><br />For low speed operation like trolling I would use a Champion J8C (or the modern equivalent of the J8J), gapped at .030. For sustained high speed use go with the J6C, at .030, as Rick suggests.<br /><br />Good luck.
