Yeah, spinning then engine without the plug with a starter will blow the excess fuel out. You can also do what mike posted by holding the plane exhaust port down, rock the prop back and forth, then let the fuel drain out of the muffler. Probably won't happen evry often. But if it starts doing it enough to take the fun out, consider several way to fix the issue. If the fuel is draining into the carb, get some hemostats and clamp off the line to the carb until you are ready to fly. If it is due to tank pressure during fueling, can still use the hemostats to block the line during fueling or use a 3 line system, etc.