As for spark plugs, yes, as Dale says… proceed with caution. Modern champion plugs are a little longer porcelain than the vintage ones. This puts the spark terminal dangerously close to the metal cover shroud. You sure don’t want any arching going on under that shroud. The solution that I found is to use short body plugs. unfortunately, the short Champion plugs like J17LM’s have non removable integral push -on type terminations. The Zephyr’s use ring terminals that require screw on nut type spark plugs. I found a very happy solution to this problem… NGK -BM7A plugs are short ,and have screw -on terminals, push on or nut type. just one small issue with these, the thread is metric 4-.07MM so if you need nuts you will need to go metric. These plugs are a medium heat range and run very well in our smaller outboards. Total length from gasket face to terminal end only 1 – 1/2 inch.
Joe B
Joe and Edwin I found some champion plugs with screw caps on them. Maybe they come with or without!
dale
