1951 case D float adjustment

[LukesCaseIH]

Flip the carb upside down and blow into the fuel inlet.
If you can hear air coming out, then the needle and seat are bad. You shouldn't be able to blow through it upside down.

I have done that and no air leaks out but the weird thing is some times it will stick close when I test it like that.

 

[Tgrasher]

Regardless of your hopefully fixing the float/needle valve problem, put a 1/8 th inch ball valve in line to be able to easily shut the gas off. The sediment bowl valve will wear by continually using it and it will become leaky too. Too many times I turned the key on a perfectly set tractor only to throw a glug of gas into the cylinders from a leaking needle valve.