The Stovebolt Site Forums The Shop Area Engine Shop Rochester B1 carb

Starting with the tank, gunked-up fuel screen, plugged line to pump, broken pump (or worse, worn pump lobe on camshaft, replace with electric pump), clogged filter...
Inside the carb, stuck float or stuck float needle, REALLY badly adjusted float.
Since you are waiting for the kit, you could open it and see how the float is sitting and whether the float needle is stuck. If you remove the bowl top and hold it upside down, the float should sit about level (no, not the proper precision measurement, but it'll give you an idea). With the top right-side-up, the float should drop to an angle that wouldn't bottom out in the bowl. The float needle should follow the float tang that holds it.
As for the other parts, with the fuel line off the carb and a bowl under the open line, have someone crank the engine and see if fuel comes out. Work back towards the tank, one joint at a time to find any blockages.

Oh, and speaking from experience, make sure the valve on the bottom of the tank (under the cab) is open. It's annoying to troubleshoot the whole system only to remember you closed this valve months ago to do something else...