I'm not sure why, but I do not have full throttle when connected to my Pixhawk. The reason I say this is that when I am at half throttle all motors spinning (Y6, newest version firmware loaded), but when I place the flight mode switch to RTL my motors more than double the RPM. I am running 4S 11AH Lipo and my motors are 400 KV. My radio is Futaba T14SG with Futaba R7008SB receiver connected via S-buss to the pixhawk. I have gone through the Parm's with a fine tooth comb. Cannot find anything out of the norm. This only happens when I switch from Stabilize to RTL. When I switch back from RTL to Stabilize my throttle drops back to where it was before making the flight mode switch. But I cannot get the motors to run as fast as they did whilst in RTL mode. In fact from half throttle on to full throttle there is nothing but my stick movement on the TX, no increase in RPM. I'm not running props on this thing until I find out what the problem might be. Fear of this Y6 climbing to 10 kilometers or more just frightens me..As of today I have not flown this Y6. Has anyone experienced this problem and if so what did you do to correct?