I recently acquired a Hangar 9 Super Cub powered by a stock ignition G26. I have no idea when the last time the engine was run but suspect it has been a while. The engine would fire up and run for about 3 seconds with the choke on and them abruptly quit. It did this about 5 or 6 times before I gave up on it. It would not fire up at all with the choke off. Does this indicate that the fuel pump diaphragm has stiffened up and if so, will the diaphragm limber up after some fuel is run through it? Any suggestions as to what may be wrong are greatly appreciated. A new fuel tank, stopper, fuel line and in-line filter have been installed. I intend to check that out today.
Thanks in advance,

Regards,
doubledee