wolf i have had the same problem .....with what i have understood as "surging idle" on one of my efi scooters (non kymco) and seems to be associated with ecu deployment......the scooter will idle at 1500 rpms (on spec) and than jump up to 2500-2700 rpms....than suddenly ....come back down to 1500 again...this happens mostly on start up but i have experienced when stopping for a light ...
the problem is infrequent and intermittent/// but opens up a pandora's box of possibilities....i have 8-9 sensors on the scooter .....you need to have your mechanic take some voltage .ohm readings especially if the problem is recurrent and you begin to loose power,,,,,,one place to look is the pts (position throttle sensor)....but hey could be others as well (i,e, air intake .temp etc....re....clutch.....if you are up yo it remove tran cover(put scooter on center stand) and visually inspect action .movement on variator and bell.clutch....