I have a 2003 650 prarie that will not start. The engine will turn over and there is spark. There is gas to the shut off. tried draining the gas from the carb, new plugs, putting gas in the carb. Also tried starting with the choke on and off. All it will do is turn over. This problem occured after being ridden all winter without a problem. Last time it someone rode it, it was parked and turned off overnight. The next day it would not start. Does anyone have any suggestions.