Home › Forum › Ask A Member › 1979 25 Johnson spark plugs › Re: 1979 25 Johnson spark plugs
June 5, 2015 at 1:30 am
#17624
Yes, QL77JC4 Champions will be fine. The L78V was a plug for sustained high RPM use. It would no doubt foul on you at slow idle speed and general use.
Dan in TN