Yes, adjust the sync screw while the bike is sitting there idling (or racing at 3K). That's the only way you'll know if and what your adjusting is doing. If it does start bringing the idle down, eventually you'll need to start turning it back up with the idle speed screw on the left carb or the bike will stall.
Yes, if the sync adjusting does nothing then it could just be lean carbs. Like I said, this '76-'77 set is quickly out-paced by mods. You should also check the float settings. If they're way off to the lean side, that will affect it too.
Yes, if the sync adjusting does nothing then it could just be lean carbs. Like I said, this '76-'77 set is quickly out-paced by mods. You should also check the float settings. If they're way off to the lean side, that will affect it too.