Help! Carburetors rebuilt and have fluctuating idle

[jdkirby]

I have rebuilt the carburetors on a 1996 Johnson 200hp venom and after placing carbs back on the engine the idle is fluctuating. It will idle at 1500 at startup then after 20 seconds it will climb up to 3000 for a few seconds then return to 1500...then same thing again..

 

[Dhadley]

Re: Help! Carburetors rebuilt and have fluctuating idle

Sounds like its going in and out of Quick Start. What happens when you try to set the idle down?

 

[jdkirby]

Re: Help! Carburetors rebuilt and have fluctuating idle

I did not try that yet. Even when it does idle at 1500rpm that seems too high...I've rebuilt alot of holley carbs back in my younger days when I was racing but this is my first marine carb rebuild. Should the motor idle around 1100 rpm? I will try to set it down this afternoon and see what it does. I turned out the air/fuel mixture screws to 1 1/2 turns but the motor wouldnt start...I pulled them out to 2 1/2 turns and it stays running

 

[Dhadley]

Re: Help! Carburetors rebuilt and have fluctuating idle

With no backpressure youll probably end up at about 1100 or so like you say. In the water itll come down. It should idle at about 650-700 in gear in the water.