1990 Johnson 60hp BAD idle

[Chilly Willie]

Hello everyone - my first post after lurking for a long while.

I have a 1990 Johnson 60hp that starts to bog down badly around 1100 rpm and eventually will die out (makes an odd sound like it's missing or sucking air). Any lower rpm and it dies instantly. It runs good at high rpm.


I just ordered a manual for it, but hoping in the meantime I can get some input.

How do you get the carbs (3 of them) off?
- I want to remove the carbs to check them over, but I can't figure out how to get them off. I see the nuts on the mounting studs from the intake manifold, but there isn't enough room to get them off because they butt up against the carb. My next thought then was to remove the entire intake manifold with carbs attached but I can't get on the bottom 2 bolts.

Leaking fuel on primer solenoid tee
- I found that I'm leaking fuel around from what I believe is the primer solenoid tee fitting. The lines on this tee are zip tied but still fit very loosely on the fitting (I can easily pull them off and on) and fuel is obviously leaking. Other lines also have no zip ties/clamps where they meet fittings. Any chance that this leaking is causing my problem (not getting adequate fuel when at lower rpms)?


Thanks!!
Willie

 

[1960-lonestar]

Re: 1990 Johnson 60hp BAD idle

i have the same issue and yes im told thats its a carb rebuild issue but if your not a carb mechanics its probly a good idea to have a cretified mechanic work on them becouse they have to be just exsact or you'll still have more issues there censitive and have to be link and sinked exsactly the same floats needle seats ect,,,, believe me its worth it , and for fuel lines they need to be air tight even fuel fittings clamps excet,,,,, install new lines that will handle e10 gasolines and makes sure your tanks are clean and aslo your fuel filters too.

 

[tashasdaddy]

Re: 1990 Johnson 60hp BAD idle

you have to remove the air silencer, and move the fuel pump out of the way, you may have to remove starter. use and open end wrench and they come right off.

 

[HybridMX6]

Re: 1990 Johnson 60hp BAD idle

As TD said, use an open end wrench, and as you loosen one slowly move it out like you are pulling it off. This will enable you to get the nuts off and out of the way. You will also need to disconnect the linkages for them.
As for the fuel lines, when you get the carbs off, take the hoses to an auto store and get new lines for it that are made to handle the ethanol in gas today, and while you are at it get the right size "T" and any other fitting you need. Also get some new zip ties as that is how you put it all together according to the manual (I have a '93 60hp).
And the carbs are not as difficult as mentioned above, I have never done carbs of any kind in my life and I did all 3 of this engine myself. Just remember, follow the rebuilding directions very well, do not skip any steps, even if it looks like the carb is spotless, and you will have to reset the idle when on the water. The manual will cover this, but the idle screw on mine it said to set 1.5 turns out, and all 3 of my carbs ended being happy at 2.25 turns out, so when you get them rebuilt and put back on, don't get upset if it won't idle, try using the idle screws a little bit and see if you can figure it out.

 

[Chilly Willie]

Re: 1990 Johnson 60hp BAD idle

Thanks for the info everyone!

The carbs were rebuilt last year right around this time by a local mechanic, gas tank and hose/bulb replaced. Ran good until about the end of the year, then the power pack went out which was also just replaced.

So I'm hopeful that the carbs should be in pretty good shape, maybe something just stuck in one of the low speed jets. I'll try a smaller bodied wrench tonight and see if that lets me get at the nuts on the mounting studs a little better.

Think the first thing I will do though since it will be quick is to get the connections tight so there is no leaking just to see what effect that has.


Thanks again!
Willie

 

[HybridMX6]

Re: 1990 Johnson 60hp BAD idle

It will help, mine was leaking after I reassembled everything. I had hoses leaking, the carbs weren't tightened down all the way, among other things. I had to take it all off again and retighten everything down very well, and in some cases even double ot triple zip tie some of the hoses and connections. It's not leaking any more though.
Ultimately, my answer was the idle speed screw and also adjusting the throttle linkage. Mine had been disconnected for a VERY long time (I bought this used as a project, so who knows for how long it was undone and played with). Since yours just started acting up all of a sudden, I'd doubt it's the linkage, and most likely not the idle screw either unless it managed to vibrate loose.