I have a 2001 polaris sportsman 500 ho. Starts and runs fine. After it warms up it starts running rough. I manipulate the throttle to try and keep it running. It back fires out exhaust and dies. Sometimes will start right up easy but will not stay running. I have new battery it is charging at 14.5 volts. New carb with new fuel filter. Does it sound like a fuel or electrical problem to you. Thanks for input.