if the machine sit a week or so, needs to be pumped first, doesn't seem to keep the ball pumped up and stay there, so is it the ball or the lines or both, You can pump it up, but doesn't seem to stay there, looking for a few thoughts, thanx
make sure the fuel cap is vented....may be creating a slight vacuum in the tank while running then pulling fuel back when sitting?It means you have an air leak somewhere. Both ends of the fuel line should be submerged in fuel, this is the pickup tube and tap off lines. Do you have any wet patches between injectors? this could be a point where air may be getting in.
If there are no leaks, no matter what the state of the one way valve on the hand primer, it should not need pumping to re-prime the system. The lift pump should generate the pressure to the injector pump and it should spring to life.