Some parts from generic GY6 engines do fit on Kymco, but from my experience you can't know if it will work the way it should until you actually put in on.
I had to change the vacuum membrane on my Agility City 125, bought a GY6 membrane, and it did fit, but the trottle response was not good. Had to buy original Kymco for it to work properly.
Same thing with the R/R.
It had all the right color wires on the right places, looked the same as the original, but as soon as I connected it all the lights turned on without the key in the ignition!
Sent it back and got a refund from the seller that had Agility City on the list of scooters it should work on.
Bought original Kymco and it works.
Kymco parts are waaay more expensive then GY6 parts