Throttle problem?

OK, got my bike running pretty decent, but when I hit the throttle and then let off the rpm's kind of hang there for a minute before they drop back down slowly. There was a little bit of play in both throttle cables so I adjusted them. That made a noticeable difference in accelerating, but did nothing for the decelerating. Is it something in the carbs not cutting off fuel to the engine fast enough when I release the throttle? Can someone point me in the right direction?

Sounds lean. Try richening your pilot circuit a little at a time.

Thanks, I will do that.