I would remove the carb bowl and play with the float to see if gas trickles when the float is down. Improper float adjustment can cause fuel not to flow also. I assume you rodded out all the ports in the carb with fine wire and checked that they were clear of obstructions. Sometimes a bad spark plug will fire out of the cylinder, but not under compression or when it warms up.
Bad spark plug wires will work dry, but ground out around moisture too.