It's usually a good idea. If the float needle has a little wear on it, or even a small piece of dirt lodged in it, preventing it from closing all the way, you can end up with an engine filled with fuel if you leave the gas on, making cold-starting nearly impossible. Personaly, I drain the float bowl before I put my bike away (just loosen the drain on the bottom of the bowl), to prevent the standing fuel in the float bowl from leaving deposits in the jets as it slowly evaporates.
Well, a broken ring won't cause plug fouling on a two-stroke, but it will destroy the cylinder. I doubt that is the problem. It sounds like either the float is sticking, or you have blown a crank seal. Try pulling the plug out, hold the throttle wide open and the kill switch on (to prevent a spark from igniting the gas fumes:eek: ), then kick the bike through about a dozen times to clean it out. Install a new plug and see how it runs.
