Let's be careful here. Jalex posted a photo of the choke cable for one carb, illustrating two cable screws: the #1 screw (upper screw in the photo) is the one that clamps the choke cable's outer casing to the carb; the #2 screw (bottom screw in the photo) is the one that clamps the choke cable wire to the choke cable linkage. The way I read it, he was asking whether he should loosen both the #1 and #2 screws on both carbs (which, of course, would lead to brand new problems).
So, JAlex: If you're reading this, when Mark Maras tells you to loosen 'both screws', he means that you should loosen the #2 screw on both the front and rear carbs. Do not loosen the #1 screw.