RE: 2s on Micros?
I think I see the problem. You bypass the ESC in the rcvr and use the external one as shown in my first pic. You use the rcvr as a normal one without an ESC. If you don't have it already, the Spektrum website shows, under the AR 6400 rcvr. you can download a page to reprogram the rcvr. to do many things. It tells you where to apply the power from the ESC and where to connect the ESC to control the throttle speed.