I have a GWS slow stick which is strictly stock and it uses a 5 amp ESC. They also recommend a 7.2 V battery pak. I get 7 minutes static on the 400mAh 7.2 battery and much more in the air by throttling back. If you are going to increase the voltage to the stock motor from GWS check with them to see if the motor can take it. The higher voltage will undoubtedly shorten its life and it will certainly require a higher amp ESC. The GWS website will get you Taiwan so skip that and go to Horizon Hobby and get their recommendations.