The pump diaphragm works only with the engine running, it has no function when you're choking the engine....
With the venturi completley closed off the suction from the piston pulls fuel into the engine through the inlet needle...If you can't get fuel when choking the inlet needle must be stuck shut...If you doubt this, take the diaphragm under the cast cover out of the carb, put the cover and gasket back on and choke it, you will get fuel if the needle is not stuck...