The most effective thing I have found with the AC Super 9, is to rewire it to accept a Minarelli CDI. This is the one I use:
http://www.partsforscooters.com/50cc_Minarelli_cdi_169-117The GY6 CDI boxes do work, but I have found that they still leave a "sluggish" throttle response in comparison to the Minarelli.
~Josh