1976 Johnson 85hp idle mixture?

[TheOutboardKid]

Hello all,

I have a 1976 Johnson 85hp model: 85ETLR76G

It has always idled kinda rough and I'm not sure why. The motor was compression tested in May, all four were between 109-113 psi. The spark plugs have been changed, it has new gas, and the carbs I rebuilt earlier this summer. Most of the ignition system was replaced two years ago by the previous owner when he had trouble with it, and that solved his issues. All four plugs have good spark. It idles at an okay RPM but has always seemed like it was running pretty rough. Does my motor have idle mixture adjustment screws? There is a chance I could've changed a screw position when I rebuilt the carbs.

Any help is appreciated...

 

[racerone]

Inspect diaphragm on the fuel pump.-----Very correct , there are no idle mixture screws.-----And there is very little that can go wrong with these carburetors.--This means motor must be in top condition for everything to work.----You compression numbers tell me the motor needs work.-----So remove the 4 bypass covers to inspect pistons / rings.----You find 2 covers on each side of the block.---Six screws each cover.

 

[TheOutboardKid]

I’ve actually had them off before, three of the four were leaking just a little bit and I decided to replace all of the gaskets. The pistons had a little bit of visible wear, but I didn’t see any large scratches or gouges. I know the compression isn’t great, but I don’t really have a ton of budget for this project. I’m willing to do some things, but if the engine idled rough it isn’t the end of the world. I don’t have the money to do a rebuild. If there is something fairly minor I can do, I will, but I really don’t have the time or money to do a full rebuild or pull the powerhead or something like that.