[cjlinkster]

You could always pull the fuel line from the pump and blow air down the line. If you hear the gas bubbling in the tank, then the line should be clear. If any of your lines are dry rotted or torn, the lines could be allowing air to enter the line and causing the pump to lose its prime.

I recently installed a new tank, and it took a more than few attempts to get the fuel back up the line to the carb.

I finally used a trick; I poured a little gas directly in the carb vent tube, and after a couple of starts the gas was flowing again.

good luck