8hp Johnson spark gap

[Yamauser]

I would appreciate it if someone could tell me the correct spark gap for an older (1978?) Johnson 8hp made in Belgium. I would even appreciate informed guesses. Thanks

 

[JB]

Re: 8hp Johnson spark gap

Over the years OMC used both .030" and .040". Current recommendation is for .030"

 

[Vic.S]

Re: 8hp Johnson spark gap

Champion QL77JC4 ( or QL86C ) gapped at 0.030"

Are your sure about the year? What is the model number?

 

[Yamauser]

Re: 8hp Johnson spark gap

Thanks for the info. I last gapped them as .035 and it is hard to start, .030 sounds better. I'm not sure about the year, I forget the code word, but the serial number is j8srlcob and the model number is 8100269.

 

[Vic.S]

Re: 8hp Johnson spark gap

j8srlcob is the model number

That's J for Johnson, 8 for 8 hp, S for sail version, R for rope start, L for long shaft (20") and CO for 1985.

The word is INTRODUCES but that system only started in 1980

the original plugs would have been L77J4 or QL77J4 probably gapped at 0.40"

(L78V for high speed running on the non sail versions)

You should not have any problems starting with a gap of 0.035". My 1984 6hp sail version is still gapped at 0.040"

 

[Yamauser]

Re: 8hp Johnson spark gap

Thanks Vic. I gapped at .030 and it starts easier. It is nice to know the motor is newer than I thought.