I have the same exact problem... Except mine won't idle, when I let off the gas it just stalls, also no power in the high end and almost none in the low end. I tried adjusting the a/f screw on the side of the carb which helped a bit then I started playing with the idle adjustment on top which did absolutely NOTHING to the idle which I found fairly weird. All stock just rebuilt everything on the machine, new top end, low end, crank case, reeds, carb, brand new stock jets, cleaned the whole carb so it's spotless, removed the parking break but didn't do anything with the wiring for it. Could the parking break wiring be causing the problem? Also yesterday it was not starting but then I connected the tors and it will start now.