It might be the primer itself, the correct way to change a filter is: DO NOT FILL THE FILTER WITH FUEL FIRST!!! Thread the empty filter on and tighten, plunge the primer up and down until it is tight, then start the engine at 1/3 throttle, if it stalls, re-prime. If you have to do more than 50 pumps, I'd say the primer assembly is shot. And the reason you do not fill the filter first is because you are putting raw, unfiltered fuel into the canister, so any dirty fuel makes its way to the injection pump.
Thanks for answering, I took apart the fuel pump and there were little yellow plastic shavings caught in the check valves, from a fuel can. Once cleared the hand primer and fuel pump worked fine.