I would look at all the fittings conected to/from the carb and fuel tank. If the leak continued after you stood it back up, i would be willing to bet one of those came loose, or off...especially if it drained your tank dry. if the leak came from the gas cap, this might not be the case. i would wipe down the spilt fuel as much as possible, take the air cleaner out, and let things air out for a few hours bewfore trying to start it up again.