spark plug gapping

[cjbc505]

what is gap for plug spl77jc4 used on 9.9 Johnson 1982

 

[racerone]

It will run fine gapped anywhere from 0.030"---0,040"

 

[oldboat1]

My '82 is happy at .030, but not sure at the moment what Champion plugs I have in it.

 

[Vic.S]

what is gap for plug spl77jc4 used on 9.9 Johnson 1982

The recommended plugs for that engine are now Champion QL77JC4 or QL82C gapped at 0.030"
When new it would probably have had QL77J4 plugs gapped at 0.040"
QL77JC4 replaces those and sometime in the 1980s the recommended gap was reduced , across the board to 0.030" Nobody now seems to remember the reason for the change in gap.

If you happen to live in a country ( almost every country except the USA ) where NGK plugs are more common BZ7HS-10 are the ones to use ( not resistor plugs such as BR7HS-10)

 

[oldboat1]

That was addressed some time back, but darned if I can find the thread or whose post it was. And maybe it's one of those phantom memories....

 

[82rude]

I find champions easy to find in Canada.OMC has recommended champions forever!Even my etec uses iridium champions .A spark plug is a spark plug cant be further from the truth especially when it comes to omc.If you due lots of trolling .040 is a better gap.