You could trying running a small hose to a gas can near the fuel pump, then turn over the engine to see if it pulls gas.
I had a problem years ago where no fuel was getting to the carb. But when I by passed the tank, etc, it worked fine. Turned out that when I had dropped the tank to replace the sender, I pinched the fuel line when reintalling the tank. Maybe you can a cut/hole in the line, and its sucking air?