Can anyone tell me what this part is called and where I might find it. It screws into the front of the carb and the fuel line from the fuel pump connects to it.

I thinks it might be a needle and seat assembly

 

Im pretty sure its just a fuel inlet valve. It is supposed to be there so if you remove the fuel line the fuel in the carb doesnt run out all over the engine. I believe it also helps to regulate the amount of fuel entering the bowl, maintaining the optimum fuel level in the carb.