Re: 1967 3hp Johnson JHR-22C
Welcome to iboats.<br />Ideally, you want to be using Champion J6C spark plugs, gapped at .030" (.76mm). <br /><br />PS - Although the manufacturer of your engine has always specified 50:1 for it, there's a knowlegable person here that suggest you should run that particulair engine a little richer at 40 or 32:1. <br /><br />I hope this helps!
