please help with idle issue

[cobra grover]

It is a 1989 Evinrude 8hp. It will not idle without pulling out on the choke just slightly. If you push the choke in it just runs out of gas and dies. I found a crack in the fuel pump and replaced that. Still would not idle. sprayed a little carb cleaner around the side of the carb and it picks up like it should so I think the gaskets on the carb are leaking so I put a new carb kit in. Still will not idle and spraying the side of the carb helps it idle. Can't figure out where it's leaking.
When we put the carb kit in I had two pieces left. A very small rubber tube about 1 1/2 to 2 inches long and a small dish shaped piece about 1/2 inch in diam. The only place I see that could go would be on the side of the carb where there is a mesh screen.
Any ideas?

 

[Daviet]

Re: please help with idle issue

What is your model number, was the kit an OEM or after market kit?
I think you still have a problem with the low speed circut in the carb.
I think the tube you are talking about is the flex tube for the low speed circut, should have replaced it, and checked the passage in the nozzle that it attaches to.
The dish you are talking about sounds like a core plug for the top of a carb with a metal top, by the parts breakdown I was looking at your carb has a plastic top.

 

[cobra grover]

Re: please help with idle issue

Thanks for the quick response. OEM kit with float. I was looking at some youtube videos and I think the dish shaped disk was a welch plug. Still not sure where it goes in the carb. Not sure either about the flex tube. When I opened up the carb there was no little rubber tube anywhere. If I left that out it certainly would cause a problem. It connects what to what? My carb has a plastic top.

 

[cobra grover]

Re: please help with idle issue

Anybody?
I don't want to take this thing to a marine mechanic but if I can't figure it out I may have to. It has to be an air/vacuum leak. I just can't determine exactly where.
Thought it was the fuel line connection to the carb...put on new lines with zip ties. Thought it was the bowl gasket so I put in the rebuild kit. I didn't see any cracks in the bowl.
Stumped and frustrated.

 

[oldybutagoody]

Re: please help with idle issue

I'm not familiar with your engine but it does sound like it's sucking air and therefore staving for fuel when it's on the low idle circuit of the carb. Is there a packing nut around the low speed needle that is loose and allowing it to suck air? (Think of drinking through a straw with a hole in it.)
As for extra parts in a carb kit, that is common because the kits are made to work for multiple engines.
It you carb does have a welsh plug, remove it to clean under it and reinstall the new one from your kit.

 

[oldybutagoody]

Re: please help with idle issue

Just to clarify the problem, It's a low idle issue but runs OK when you throttle up?

Shot in the dark but is the gas tank vented?

 

[cobra grover]

Re: please help with idle issue

It seems to run ok when throttling up but it won't stay at a constant rpm if you push the choke all the way in. It has to be sucking air somewhere around the carb. I just can't pin down where.

 

[cobra grover]

Re: please help with idle issue

The motor is model number is E8RCEC. Gas tank is vented. I agree with Admiral that it is a low speed circuit problem in the carb. The slow speed adj screw seems to have no effect at all as to how it runs.
Again, runs with the choke out just a little but if you push it in you better be ready to rev and pump the throttle. Can't keep an even rpm. It will just slow down until it dies unless you pull out the choke.

Any more ideas?