96 Formula Z 583 Bar riser issue

so after installing my new 4" riser on my formula, if i turn it sharp left, RPMs go up! not gonna lie i about pooped myself when i went sliding across the garage and hit the wall! haha it seems that the cables are just a tiny bit tight, can i just screw the adjustments on the cables where they go into the carbs and just loosen them up a bit, they are nearly all the way screwed out right now, the sled has nearly 6k miles on it and im sure the cables have stretched but i was wondering if i would have the room to gain?

let me know what you guys think!!!
thanks