Last winter I was able to start my sled but would only stay running with choke on full. After getting on the lake nad opening it up a bit, I was able to turn the choke off and would get around normal operating levels, but would end up bogging down and dieing if I did not turn the choke back to full. Is (does) this sound like dirty carbs? If there is something else that it oculd be, please let me know, its going into dealer this upcoming week and would like to get ideas if it is something else. Thank you very much for any info that gets posted.