it is a fuel problem, it has a restriction somewhere filter, hose, filter screen in tank,see if it run out of a can of clean fuel. have seen these fuel line corrode to the point on restriction, if it will run on clean separate fuel out of a can then you need to start at the back Fuel tank and work you way forward until you find the problem you could take the line loose at the tank and at the front and blow compressed air and see what you get out of the line stick the line in a container and see wht you get out of it, trash in the tank filters it all happens with age..........let us know