Spark Plug gap 1978 or 79 Johnson Sea Horse 115hp?????????????

[Lawdawg69]

I have a Johnson 115hp Sea Horse, either a 1978 or 79 model. I'm fixing to change the plugs and nned to find out the correct gap for the plugs.

 

[Joe Reeves]

Re: Spark Plug gap 1978 or 79 Johnson Sea Horse 115hp?????????????

Plugs should be Champion QL77JC4 plugs. The original recommended gap was (from 1973 to around 1990 or so) .040 . Later it was changed to .030 for some rerason. Various engines seem to show improved performance (idle or full throttle) with one gap or the other. Try both and decide.

 

[Lawdawg69]

Re: Spark Plug gap 1978 or 79 Johnson Sea Horse 115hp?????????????

Thanks a bunch. Do you know anyplace you can down load the repair manuals on line for a motor this old? It's in good shape and runs great, I just like to have one around in case of problems.

 

[wilde1j]

Re: Spark Plug gap 1978 or 79 Johnson Sea Horse 115hp?????????????

The only one worth owning is the OEM shop manual. The third party ones make good coasters to sit your beer on. Try Ebay or outboardbooks.com.

 

[HighTrim]

Re: Spark Plug gap 1978 or 79 Johnson Sea Horse 115hp?????????????

The only one worth owning is the OEM shop manual. The third party ones make good coasters to sit your beer on. Try Ebay or outboardbooks.com.

Second that. A used one on ebay will be cheaper than the ken cook manual. May have a couple grease stains, but that only gives it character

ALso post the model number so that we can give you an accurate year