My blade cx isn't flying right at all it keeps counter rotating right even with the trim and the resistor adjusted left it isn't getting more than 8 inches of the ground and it sounds strange when it runs it was flying great the day before then it just flew terrible the next day I touched it
I tried hooking up another battery that was in good shape and it still did the same thing I found out that one of the motors was bad I replaced both motors and it still was flying bad then I replaced the 4 in 1 and it still doesnt work right I cant see what else could be causing this problem the mechanics are fine and the shafts are fine the only thing I think that could be bad is the frequency chip that goes in the reciever but it has no range problems I need some help please I realy like my cx and I feel terrible that it keeps not working

the inner shaft may be binding. did you check to make sure it rotates freely when you r&r'd your motors? if not, just pull your right motor out so the upper blades turn freely, and give the upper blades a spin. they should spin freely without friction while the lower blades remain still. if not, fix whatever is binding (bent shaft, bad bearing, etc...).

hope this helps,
kev

[edit: sorry, i didn't catch that you already said the mechanics are all good.]

Make sure your swashplate hasn't become separated. I had mine sepate and it was unstable, all over the place.

Skarn

Also, besides binding, make sure your inner shaft reaining collar is properly tightened. If the set screws on the retaining collar aren't tightened on the shaft flats, the drive gear will spin around the shaft and unbalance the anti-torque effect causing the aircraft to spin.

Ya that happened to mine. I didn't tighten the collar right and suddenly my BCX2 started to sound really weird, rotate counterclockwise, and not be able to lift beyond about 6 inches. Tighten that collar properly and you'll be fine. Also I clued in when hitting the rudder right and raising the throttle to the point where the upper blades kicked in resulted in the blades slowly spinning up, but the motor RPM remaining constant.

damaged or missing tooth on outershaft gear will also cause discussed problem.