Re: 16G fuel pump issues
Just buy a new fuel pump. I don't know if anyone has kits, but its not worth the trouble in my view.
They have little rubber flapper check valves in them - they are likely stuck or broken - and yes if it was old, and you let it dry out, the check valves or the diaphragm have now failed.
This is why I don't believe in fuel shut off valves or running engines dry for storage.