I’m with OK and MGMcAnick on this one.
Soak the carb in a bath of real carb cleaner, (not your gumout spray can stuff), and make sure the fuel from the tank flows freely down to the carburetor.
On a slightly related note, 40 years ago I rebuilt an engine on a '54 Ford 4-cyl tractor (it was seized). After putting it back together, I spent two days trying to start it, without any luck. It would run for a second with a spray of ether, but that was all.
I called a local Ford tractor dealer to ask for any input. They told me I had to remove the spark plugs, squirt a bit of oil into each cylinder, and try again. They said they had to do that with all the new tractors (off the truck from the factory), otherwise they wouldn’t start.
The oil was needed to “seal the rings” to increase the vacuum for the updraft carburetor to work correctly.