I hope that this is the appropriate place to ask this question. If not, please let me know.

I have a 2005 KTM 950 Adventure. Having not ridden the bike in about a month, I fired it up in the garage. At idle, it was immediately obvious that it was running roughly on one cylinder. When I turned the throttle, it would backfire from the right exhaust can. My initial thought is that the fuel had gone bad (though unlikely) or a carb float was stuck. But before I start looking into the problem, I wanted hopefully get some feedback as to other possible causes. Keep in mind that the bike had run perfectly beforehand. So I suspect that the cause is something rather minor.

I would appreciate your thought. Thank you!