Best spark plug and gap for my 1983 Johnson 140 hp V4

Joined
Jul 14, 2011
Messages
9
I can't wait for my service manual that I just ordered and want to change these out now. Don't trust what's in there now either. Could someone please recommend a good plug and it's gap?

Thanks a bunch!
 

bruce--69

Cadet
Joined
Jul 12, 2011
Messages
14
Re: Best spark plug and gap for my 1983 Johnson 140 hp V4

OMC motors came out with Champion plugs, that what I always went back with. NGK for Mercury. Dont waste your money on any other plug that boasts extra performance, go with the stock spark plug, its not worth it.
It will either use an L77JC4, or a surface gap plug UL77V. See what your manual tells you.

Bruce
 
Joined
Jul 14, 2011
Messages
9
Re: Best spark plug and gap for my 1983 Johnson 140 hp V4

Bruce - Thanks man solid advice. That's whats in there now. When I pulled them out they were like new. I started this motor this weekend after it has sat for over 6 years. Amazing...
 
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