1958 Fastwin 18hp 15024

[mhanna2755]

Question about spark plugs. After searching here and Google i see most people recommend champion J6C plugs. Where my question comes in is Champion's website and iboats parts catalog say to use a J8C and the Evinrude service data pdf that I found in these forums says J4J, which I assume is a J4C. Will the hotter J8C plug cause problems? What is everyone's opinions on this? The J6C's are scarce locally, but i can get the J8C's easily. I can order the J6C's online, but i hate doing that when i can walk in and buy locally.



Thanks,
Mark

 

[gokart83]

Re: 1958 Fastwin 18hp 15024

check the lenght to make sure they dont hit the pistons and try them! If they dont foul out or cause it to overheat, your prob good. Just look at them after hard running and make sure they match what a proper tuned plug should look like(pics are easily found online) If they are close, then its prob just a matter of tunning the carb alittle. Once tuned, Go fishing and laugh at they guy that cant even start his brand new motor. (you can spot them by the tell tell look of disappointment while the hood is off and there very clean hands).

 

[SeaKaye12]

Re: 1958 Fastwin 18hp 15024

check the lenght to make sure they dont hit the pistons

Seriously! There's not much extra room. I screwed my compression tester in up to the o-ring and it hit a piston....Mine's a 1960 18HP

Chuck

 

[kfa4303]

Re: 1958 Fastwin 18hp 15024

I run Champion J6C on my '66 20 hp which is virtually identical to your motor and have never had an issue at idle or WOT. While you'll probably be ok with the J8C plugs you do run the risk of running too hot. Perhaps the auto parts store can order them for you without charge.