Barry, Thanks for all the info. I still haven't gotten around to taking the Y harness out and switching the servo to another channel but I will. I ordered a prop balancer and it will be here today. I think that is a big part of it. The thing I've noticed about the wing is that there is so much space between the ribs and that's what causes the "drumming". I wonder if it would be worth it to open the monokote and add ribs in between the spaces. (?) Definately take some time and add more weight. I sure love this plane. It is a kick to fly.