I am not new to heli flying since I did it back in the 80’s but after taking off over 15 years I am back into it with a T Rex. I purchased a Futaba GY401 Gyro and now trying to get it dialed in. What I am experiencing is that when I increase the throttle the tail boom swings around but once I get it back pointing in the correct direction it hovers fine with a little drift. I am using a 9C radio and was wondering if I don’t have something not setup correctly. Can anyone give me some pointers?

It sounds like your gain is turned down too low. The gy401 has a remote gain adjustment, perhaps you are having problems with that portion (I have a GY240, so not too familiar with the 401). I experienced similar symptoms with the GY240 and a hummingbird elite.

http://www.raptortechnique.com/gy401-futaba9c.htm