Mercruiser 140 running very rough at idle after carb rebuild

[Chevyls6]

Calling all rochester 2 jet carb gurus lol
What would cause an overly rich condition after a rebuild ? I set the float height and drop as per the instructions in the quicksilver carb kit. The engine runs okay above 1200 rpm but it idles very rough.

I turned in both of the idle screws all the way and the engine runs better instead of stalling like you'd expect.

Are there any areas to investigate in the carb that would cause this?

 

[Scott Danforth]

My guess is you have a fuel leak (welsh plug is one possible location). Or your float is off. If the engine doesnt kill turning in the idle screws, its getting fuel somewhere else from with the carb

 

[Chevyls6]

I have had the issue of aftermarket needle and seat kits not sealing even when the float comes up causing a flooding condition.

Does this ever happen with oem mercruiser kits?