I made my cooling doors stationary but you still need the servo to operate the lower flap part of the radiator. This 109 has two flaps per wing. the inner which is the flap under the cooling door, then the outer flap which is next to the aileron. A couple of servos on the wing are not going to make that much of a difference with the weight. I fly my plane with a SAito 150. This plane would fly well with a 120 4 stroke. A 160 2 stroke makes this plane a rocket which is not needed. I am flying at about 4200 feet asl.