1992 70hp Evinrude Carb Settings

[ochi]

Hi guys,

First post here, and hopefully it all goes well...

Just recently bought a boat with this 1992 70hp Evinrude. Everything runs great except when I try to troll at low speeds (around 600-800 rpm) the motor sputters and gives out. If I take it for a good 10 min rip around the lake, I can idle it down to 700 rpm and troll nicely for a period of time - then she acts up again.

Now I have read hundreds of topics about this and have a pretty good feel for what it might be (air leak, dirty carbs, needs resync). I have run 1-1/2 tanks of sea foam thru it and replaced the plugs so far with no luck. A gent told me that he figures its running rich which seems reasonable so I want to try to adjust the carbs. Does anyone have a good diagram or could help in instructing me on where to begin?

 

[cajun man]

Re: 1992 70hp Evinrude Carb Settings

Hi, I also have a 1992 70hp johnson, and i just rebuilt the carbs. The manual i have tells me 2 and 1/2 turns out after reseating the needle valve. Then put it water and adjust to best idle starting with the middle carb first. I have mine adjusted about 2 and 1/4 turns out. Also mine is techinally a 1992& 1/2 a bit diffrent carb, but i think the setting is the same.

 

[cajun man]

Re: 1992 70hp Evinrude Carb Settings

ok, went back and checked the manual and 1991 and 1992 70hp is only 1 turn out on the needle valve. My suggestion would be to lightly screw in the needle valve and see how many turna it takes to seat, then go from there. My 1992 & 1/2 carbs have a black plastic cover on the top of them if this helps you any.

 

[ochi]

Re: 1992 70hp Evinrude Carb Settings

That black plastic cover would be the air box right? that would be at the front of the engine? DO you have to take it off? And what does the knob look like and where is it? Just want to make sure I've got the right one!

 

[cajun man]

Re: 1992 70hp Evinrude Carb Settings

Nope, not the air silencer, on top of each of my carbs there is a black plastic piece, it's called a sv carb put on 70hp johnsons from a 1992&1/2 and on. if your doesn't have it then it's a tr carb and the slow speed setting starts out at 1 turn out. the screw is on the top left of carb with a spring on it. Hope that helps you.

 

[ochi]

Re: 1992 70hp Evinrude Carb Settings

that should help! thanks, and I'll post back after the weekend once I get a chance to play with it.

 

[ochi]

Re: 1992 70hp Evinrude Carb Settings

Ok so I went and checked and my plugs are pretty fouled... My guess is it's running rich. Checked the screws and they are all different ( top is 3 turns to seat, mid is 2.25 to seat and the bottom is 2.5) . I have a black plastic cover on the top of my top carb so I'm guessing it's an sv. Now, is it 2.5 turns or 1 turn out from the seat?

 

[cajun man]

Re: 1992 70hp Evinrude Carb Settings

Ok so I went and checked and my plugs are pretty fouled... My guess is it's running rich. Checked the screws and they are all different ( top is 3 turns to seat, mid is 2.25 to seat and the bottom is 2.5) . I have a black plastic cover on the top of my top carb so I'm guessing it's an sv. Now, is it 2.5 turns or 1 turn out from the seat?

For the sv carbs it's 2.5 turns out to start.

 

[patrick4266]

Re: 1992 70hp Evinrude Carb Settings

If you have different carbs that could be your problem.

 

[ochi]

Re: 1992 70hp Evinrude Carb Settings

Works perfectly now! Took it out on the water, shut the engine off, seated the valves and then turned them out 2.5 turns and started it up. Trolled all night without a hicup. It actually trolls just a little slower now. It could probablly use a little finer tunning but I'm happy. Thanks for the help!