Ok since you don't have drag porting,I have one more question for you.Are you running V-Force reeds in it?I will agree with odaen on your jetting being lean and if you have V-forces in it also I will garantee you are way to lean.Honestly I would put 410 mains in it and try it.I built one that I had to run 410's in it at 4500 feet elevation.Granted it was a +4 stroke with 28mm carbs but the elevation is the key word here.