As soon as I get my tricopter up in the air and the rear servo starts oscillating slightly back and forth. It is real easy to see when it is hovering out in front of me. Because of the oscillation it starts to do small jerky movements into one direction and I have to yaw it in the opposite direction to compensate for it. When I fly quickly in one direction it has a slight "pull" to the one side because of it. Any idea how to reduce it?