Could be the float clearance is not right. Does fuel run out of the carb if the petcock is left on? I recently installed rebuild kits in my 500T carbs and adusted the float clearance and viola, it runs like a new bike at 19k miles. Make sure the throttle linkage allows the idle screws to bottom out on the carb stops. Mixture is adjusted for fastest idle on both carbs first, then idle screws set the 1100 rpm. Good luck with her. These are classic, but not popular bikes with more vibes than most prefer, but Hondas firt.