1961 Johnson 40HP RDSL-23<br /><br />Seloc manual says Champion J4J<br /><br />This crosses to Champion J4C, J8C, and RJ8C.<br /><br />Should I go with the J4C (in use now) or go to the '8' with or without resistor?<br /><br />Thanks
Use J4C plugs in that Big Twin, unless you're going to be trolling most of the time. Then use J6C plugs. Stick with Champion. Gap should be .030"<br /><br />The J8C plugs are too hot for that engine.
