Have to push the choke to get up to speed

[Cucaracho]

When I throttle up it boggs down, it seems like a lack of fuel, and the it shuts off, but if I push the choke while throttling up it picks up speed and then I release the choke and it works just fine. The problem is only when picking up speed from zero. Maybe the low speed jets are clogged? what do you think.

I just rebuilt the carbs, new fuel lines, new filter, fresh gas.


Thanks for your help.
Johnson 110hp 1989

 

[Cucaracho]

Re: Have to push the choke to get up to speed

Dont know wich are the low speed jets........or could be something else?

 

[Barnacle_Bill]

Re: Have to push the choke to get up to speed

Did you rebuild the fuel pump when you did the carbs?.

 

[Joe Reeves]

Re: Have to push the choke to get up to speed

If the low speed jets were the problem, the engine wouldn't idle properly.

Did you thoroughly and manually clean the high speed jets with a piece of single strand steel wire? If not, do so as solvent just doesn't do the job properly.

If you're going to do your own work, it would be best to obtain a proper manual to avoid expensive mistakes.

 

[Cucaracho]

Re: Have to push the choke to get up to speed

The fuel pump is fairly new, about 6 months old, thats why I did not rebuilt it. You think I should?

I runs great at high speed, the problem is starting it and getting up to speed, why do you think the high speed jets might be the problem?

Joe, I will take apart the carbs right now to clean the high and low speed jets and follow your instructions on needle adjustments (http://forums.iboats.com/showthread.php?t=167352) Can I do the adjustments on muffs or have to be in the water?

I have a manual but I am having trouble finding the right info........

 

[bigpoppakdog]

Re: Have to push the choke to get up to speed

you should adjust the idle in water because of the backpressure. with muffs on it will run like a top then soon as you get it in water it will run completely different. with mine (71 115 hp evinrude), i had that problem also. took all 4 low idle screws to 1 1/2 turns out and adjusted from there while I was on the water.

 

[Cucaracho]

Re: Have to push the choke to get up to speed

I just removed the two carbs.
Have two problems:
1.- I removed the float bowl and took out two jets from top of the bowl and two from the bottom of it. I am guessing the two from the bottom are the high speed jets. On the top carb on the left side the jet is stuck and cant get it out what can I do? Any suggestion on getting it out?

2.- The slow speed jets, I understand, are the ones on top of the main carb inlets. I have read on some posts that these should be about one turn out.......so I should leave them loose?

 

[Joe Reeves]

Re: Have to push the choke to get up to speed

There are no adjustments to be made on the 1989 110hp model. The jets are fixed jets and they should be tight.

Notice the numbers imprinted on the jets. Be sure that they go back exactly where you took them out.

The jets that are installed at an upward angle in the inside top portion of the carburetor throats are the idle jets..... and they meter air, not fuel.

The high speed jets meter fuel and are in the bottom center portion of the float chamber, 2 to a carburetor, in back of the screw plugs on the side of the float chsmbers. If they won't come up, clean them where they are with a piece of single strand steel wire. Make sure they're clean.

 

[Cucaracho]

Re: Have to push the choke to get up to speed

I just finished cleaning the high speed jets. Left them 3/4 of a trun out, I will take the boat to the lake to fine tune.

Maybe its a dumb question, but I really dont know:
Where are the slow speed jets?

 

[Joe Reeves]

Re: Have to push the choke to get up to speed

You are not comprehending what we're saying. Those JETS ARE NOT ADJUSTABLE. They must be tightly secured. Tighten them up. DO NOT let them remain loose!

I also spoke of the slow speed jets (idle jets) as follows: The jets that are installed at an upward angle in the inside top portion of the carburetor throats are the idle jets..... and they meter air, not fuel.

All of the brass jets must be screwed in tight.

 

[Cucaracho]

Re: Have to push the choke to get up to speed

Got it.
Thanks.

I will try it on the lake this week, and see if the high speed jets need any fine tuning.

Hopefully by cleaning them, the problem of bogging down when picking up speed is fixed.

Thanks, really appreciate your input.

 

[Randybeall]

Re: Have to push the choke to get up to speed

In the carb throats where the throttle plate closes are some tiny drillings, usually two covered by the throttle when closed one open. They are critical to transition to open throttle. You need to check them with a piece of wire to make sure they are clear. On the older carbs there were alumnium plugs in the top of the throttle body which covered them, I do not know on yours. Good carb kits come with the plugs which you have to drill or dig out with an ice pick. Taking it out allows cleaning of the holes and the passage to the fuel and air jet for low speed.

 

[Cucaracho]

Re: Have to push the choke to get up to speed

I did remove them and cleaned them with a wire.

I am wondering one thing:
On the carb bowl, on each side there are the high speed jets and just above each of them there is one jet, should these be tightly adjusted?

 

[Tim Frank]

Re: Have to push the choke to get up to speed

You are not comprehending what we're saying. Those JETS ARE NOT ADJUSTABLE. They must be tightly secured. Tighten them up. DO NOT let them remain loose!

I also spoke of the slow speed jets (idle jets) as follows: The jets that are installed at an upward angle in the inside top portion of the carburetor throats are the idle jets..... and they meter air, not fuel.

All of the brass jets must be screwed in tight.

I think Joe was pretty definitive with his response.

 

[Cucaracho]

Re: Have to push the choke to get up to speed

Now I got it!!
Every jet tightly adjusted............
I thought the high speed jets were adjustable,
but now I understand they are not.

Thanks.

 

[modernrocketry]

Re: Have to push the choke to get up to speed

I had a very similar problem with my 115.
It turned out to be an air leak in the primer bulb.
Once I got the engine over 2700RPM the air leak would mysteriously seal itself.

Double check your fuel supply -- or try a seperate tank straight to the fuel pump.

 

[Cucaracho]

Re: Have to push the choke to get up to speed

After cleaning the jets.........problem fixed!!!
But now the motor seems to run at 70% of its power.....,
slow to get out of the hole and top speed at 30mph.
Before it was very quik out of the hole and 40mph.
I dont think it has to do with what I did when cleaning the jets........so I posted a new thread.

**I must say that this thread was very helpful and right on the problem, thank you.