This probably is carb related.
Check the crankcase pulse duct to the carb, and the position of the carb on the manifold. Make sure the hole in the manifold matches with the hole in the carb, or your carb will not pump fuel. (the carb may have been rotated 180 degrees on the manifold)

The pump petal valves may be curled up. This is easy to check by removing the pump cover. (the closed one) If the valve petals do curl up, you need a diaphragm mainenance set. The off neede settings point in this direction.

Before going on a wild goose hunt however, check the inner bronze mesh strainers in the carb. There is one in the pump, and there may be one just before the main jet. They should be clean.