3.0 litre Volvo penta wont idle

[shaners101]

Hi,
The boat is 2001 Larson SEI 190 with a 3.0 liter Volvo Penta 2bbl Holley 3100 or 3500 carburetor.
I rebuilt the engine and carburetor after the boat sank in salt water. After rebuilding I cant get it to idle. To get it to start I have to hold the throttle wide open. It runs fine at higher rpm. I suspect that it is running very rich from the black smoke. I have also run it from temporary fuel can but it wont idle. I have adjusted the idle mixture screws right it but still no better.
Is there any way of checking if the float valve in the carburetor is closing and metering the fuel properly?
Closing the choke causes the engine to die aswell.

 

[shaners101]

Re: 3.0 litre Volvo penta wont idle

I did run it briefly with no water circulating through it. This may have caused the flapper valve to fail which maybe why it wont idle. I haven't been able to find the flapper valve to see if its working, I presume that its in the exhaust down pipe after the riser as its not is the exhaust bellows. I don?t think that the flapper valve failing would prevent the engine idling?