i was riding my 08 crf 450 off and on for about 2 hrs.Everything was fine and bike just shuts off i kick it one to two times it fires up at idle,so i give it some gas and it stalls, and will not start up... So i checked spark plug,carb and they are fine. I checked the exhaust valves and they were good, but my intake vales had zero clearance. Can that make a bike just all togther stop running, and has anyone ever heard of a similar problem the bike hasn't been hard to start or anything.. please help!!!!!