TailDragon, first set it up for 0-0-0 on the wing incidence tail incidence and engine incidence. Make sure your C/G is in the range or 25% to 33% of the MAC. If your nose moments and tail moments are all with in range then it should fly great. I suspect the down thrust is causing you problems if you don't have a positive incidence in the undercambered wing. Hope this helps.