wont idle, but runs at higher rpm

[shotgundexter]

Engine will not idle, it will stay running if i continue to pump throttle. It will stay running at about 2000 rpm but if i try to idle back just a hair--rpms will drop and engine dies in about 3 seconds. It will rpm up normally, and seems fine untill i leave throttle alone.
-- i have replaced the intake exhaust manifold gasket, drained fuel added new fuel, cycled fuel through a water seperator and seperate fuel filter.
---installed new fuel filter in between tank and fuel pump- cheap inline style, took out fuel filter that is in the carburator- cleaned and reinstalled.
----changed spark plugs, the existing plug wires are 2 years old
---took out fuel line and filter sprayed with carb cleaner, removed air jet idle screw and sprayed carb cleaner in there, then cleaned the screw with carb cleaner --put all back together.
-- i have tried keeping it running for a few minutes to get up to temp, brought rpm up some but still will not come down to an idle--it comes down to die.
--is there any possibilities other than carb rebuild?

 

[ian ash]

Re: wont idle, but runs at higher rpm

I had a simillar problem with my 4.3 mercruiser. Turned out the choke flap was stuck nearly all the way shut. The choke thermostat had failed.
If you take off flame arestor/air filter have a look at your choke flap to see what position its at.when the engines warmed up it should be more or less all the way open.

I must stress im not a mechanic but this is what give me a problem very simmilar to yours!!!

 

[shotgundexter]

Re: wont idle, but runs at higher rpm

im glad to get any suggestions, i have taken the flame arrestor off and started engine and with it running i can see that the choke is all the way open-- but thank you for responding.

 

[Alpheus]

Re: wont idle, but runs at higher rpm

http://forums.iboats.com/showthread.php?t=409253

 

[Bondo]

Re: wont idle, but runs at higher rpm

--is there any possibilities other than carb rebuild?

Ayuh,.... Carb Replacement.....