The slack in throttle cables has nothing to do with cruise,the way the cruise works is the push cable when throttle is rolled off opens a switch in the cable turning cruise off. The pull cable has slack you would notice in throttle grip. If you followed this procedure (loosen both cables completly adjust pull cable to the point that you get wide open at carb/throttle body,then adj push cable for amount of slack desired,if you still have too much slack and cant get it out suspect push cable assuming you can still open the throttle probably the cruise wont shut off if that cable is broken..
Sorry meant push cable causes slack..