Use the shut-off valve, run it till it quits, then crack the bowl nut loose, or the drain screw if it has one. Thats about it, stabil is only good for 90 days according to stabil, we sell it. The gas now days, at least here in Mi. is terrible. Generators are the worst for fuel problems, we just forget how long its been, who wants to dump 5 gallons of crappy fuel into something else, so we add fresh stuff to old stuff, over and over. Whats in the carb is key, get rid of it, thats what they do at the factory.