i have a raptor 50 with a tune hitori pipe ,a os 50 hyper motor, this machine can hold a rock solid hover, it barely move with hands off. my problem is when i give it full throttle on a upward decend it snap and the nose rolls to the right and then a couple seconds later it torks to the left can any body help me .other than that she flies perfect. i was wondering is it the rudder servo im using a futaba s9250 on the the throttle im using jr ds8231 on the elevator and jr ds8231 on the aileron and nes 4131 futaba gy-401 gyro jr 8103dt heli verson radio.

Descend means to fall. You must mean on a climb? Do you mean it rolls like you gave it right aileron? Or do you mean it yaws to the right?
The 401 gyro works best with the 9254 Digital servo. If the servo your using in not at least as fast as that is you could have problems.
The way your wording your servos is confusing.
BTW the aileron and elevator servos should both be the same. And they must be good servos.