Did you blow the passages out with air and a nozzle before you assembled it?
Really sounds like you have something plugged.
Personally, I would A) remove the carb, B) remove the idle mixture screw, C) remove the top, D) spray carb cleaned into the hole where you removed the mixture screw, seeing if it sprays out the hole in the venturi, just above the closed throttle plate, then E) open the plate, seal the idle hole in the venturi with your finger tip, and spray again, seeing if you have open ports the other way.
Generally goes through an idle correction jet, and under the main jet.
There are usually idle jets, primary and secondary, high on the sides of the carb outsides, under a retaining brass threaded plug that you need to remove and blow out, too.