I have a 2004 big bear 400 4wd and i am haveing an issue with it.The problem i am having is everytime i hit the throttle it stalls out on me.It starts up fine and idles fine but once you hit the throttle it stalls out on me.Before this happen i rode it for awile and then fuel came out of vent tube in the gas cap but it only did once.Tell me what you guys think is wrong thanks.