There is a thread on runryder right now about a guy who couldn't get his HH gyro to stop hunting in a Hawk. The solution given by a couple guys was to check for windup (he was able to get 70 degrees by holding the main gear and turnign the tail rotor), and if he had it, to pinch the wire holder on the front part to minimize this. Apparently this did work for a couple of guys as they now have no problems with HH gyros.

But no doubt the torque tube upgrade would be better