Best to use gas with Stabil if you might not run for weeks/months- small bottle will treat lots of gas cheap. I haven't followed this post (I seldom drift into this forum), but I doubt new gas will improve things -carb cleaning is probably calling you. How's your tank innards look- have you pulled petcock and made sure its filter is still intact?
The gas had Seafoam in it, but it was regular gas with some unknown amount of alcohol.
The tank had a bit of rust along the bottom seam that cleaned up well with Evaporust. I installed a new petcock because the old one was frozen. I also tried the bike with the petcock on prime with no change to the pathetic performance.
I will try one more time with fresh gas, but if that doesn't work, my season is done. I will start tearing everything apart and collecting parts. I was doing a rolling rebuild, but if I have to remove and do the carbs, I might as well do everything else at the same time.
Jim