Carb - Fuel shoots up thru the main jet

[Theom]

I've got a carb on the following outboard that I can't get working:
Mercury 2007 Outboard
F9.9EXLPB
Serial 0R206664
I had a shop rebuild it because it was having problems starting and it seemed to be getting spark just fine, but not fuel. The shop rebuilt and gave it back to me and now it's shooting gas out the main fuel up into the barrel of the carb as soon as I pressurize the fuel line.

The shop said I just need to adjust the float and stopped taking my calls. I adjusted the float so it was level with the bowl rim. I also measured it to a spec I found online. I also tried over adjusting it just to see if it would shut off the gas flow and it wouldn't while installed.

I polished the needle base and made sure the needle was clean and smooth and it is.

Even though the shop replaced them, I bought a new float and needle and swapped them out and it still does the same thing.

I don't see any marks where the float is catching on the bowl.

I had a buddy of mine who is a boat mechanic tear it down and put it back together and he said everything looks good. He recommended just getting a new carb.

Any ideas? Should I just get a new carb? What weird little gasket or part would make it do this? Gas just continuously flows into the carb and out the main jet at high speed as soon as it's pressurized.

 

[Mc Tool]

Are you sure you have the fuel delivery hose attached to the correct tube on the carb .....wouldnt be the 1st time Ive seen the fuel hose connected to the bowl vent .
Otherwise the fuel is getting thru or around that float valve . With carb off the motor put a short length of fuel line on carb and blow thru it ,you should be able to blow air into the carb , then whilst blowing in tube turn carb upside down and it should then not pass air ,coz when upside down the weight of the float will hold the float valve closed . And make sure the floats actually float ....like do they feel heavy like they are full of fuel ?.
If the float valve seat is removable make sure its sealed to the carb body when fitted , there should be a gasket or an O ring in there.