If you haven't already done so, I have the Castle Creations 5700KV motor with the Sidewinder ESC.. been in there for more than a year now and works great... haven't had any issues..Its drop in simple.. I did change the pinion 2 teeth up from stock and went to 2.4 ghz as well.... some advice for you... change out the front and rear tires to GRP rubber or other quality racing tire as well... the brushless combo has so much power the stock tires will just break loose whenever you hit the throttle.. You will quickly learn throttle control.. or you will flip the bike over every time... here's a quick pic of mine before the new tires and spektrum radio...