One more word on unplugging 2 motor wires.I was using throttle hold to work on my 450.I didn't catch it but the throttle was reversed on my transmitter.When I plugged in the battery, the blades spun up at full speed.I got whacked on the arm. I had to put 2 butterfly stitches on it and a couple of big bandages.Being on plavax and a full asprine a day, it was nasty.Now I have a 2" scar. My motor now gets unplugged. I don't trust throttle hold.And I had to keep what happened from my wife. <br type="_moz"/>