if i remeber correctly, your main jet seems WAY too big.. i am running a 165 at 600 ft above sea level.. you should be using a smaller jet than me at your elevation (but engine mods will differ your jetting) IMO.. are you using a fuel filter?? what type?? maybe you are running out of fuel (sucking the bowl dry).. which could be from running a BIG main jet, a low flowing fuel filter, or using too small of fuel line?? i would cover those bases to start.. check the needle in the carb, the 2 into 1's are super sensitive to needles.. SNOP will guide your in the right direction on this one, listen to him, he has some good knowledge.. i use a EEK needle in mine , it runs perfect.