The following specs are taken from Doc Matthews 4-40 Bipe as published in RCM 10-86, Plan #977. CG should be 2 9/16" back from the leading edge of the top wing. No down or right thrust on engine. Just set up zero/zero. Suggested surface deflections are: rudder 1/2" left and right, elevator 3/8" up and down, ailerons 5/16" up and down. The 4-40 is a sweet flying bipe. Enjoy!