You have a fuel supply issue, the fuel is supplied by the pump to the filter/carb-- if you have eliminated the tank/lines/another filter/by sitting a can of gas on the fender to supply the pump then it's either the pump/eccentric/or lines at the pump or at the filter/carb. I would double-check that the eccentric is not loose again and either replace the pump or as suggested bypass the mechanical with an electric pump and I'm betting your problems will go away.