When you are running down the road, the bike is air cooled. When you stop without that air flow and shut off the bike, the temps of the cylinders increases. This in turn does cause the gas to evaporate, leaving the cylinders dry. Best procedure is to give it a few priming kicks, then turn te key and kick. Should fire up. If not, don't tickle or choke- just do several rapid kicks, and that should do the trick.