is thre fuel in the tank! have you tried blowing air back through the line and listen for bubbling in the tank. have you checked any fuel filters for plugging.is the fuel pump working as many of the older pumps  have gone bad when gasahol is used.is the carb float stuck in the closed position.maybe a crack/hole in the gas line so the pump is sucking air.maybe a new electric fuel pump would solve your problem!Good  Luck !!!