What happens sometimes is that during transport, the boxes are flipped upside down and put in that position for a period of time. As a result, the float or needle valve can get stuck. A light tap with a rubber hammer may or may not do the trick.
Even though a carb can feel like an intimidating black box, the top part of the carb (the air horn) is quite simple to open up. Basically, remove the screws you can see from the top, and the entire air horn can be lifted up. That will give you access to the float and needle valve. It takes literally 10 minutes. The accelerator pump (#3) is a frequently serviced item on old carbs, so every Cruiser owner should try opening up the air horn at least once. Do this on a table with a piece of cloth underneath.
View attachment 2121448