I just finished building the Hog Bipe myself, but due to weather I havn't got to fly it yet. I have seen the question you ask asked before about only using 2 ailerons, and if I remember right most people advised against it. There is a thread on here somewhere about it. I wish I could help more, but as I said, I have not had the chance to fly mine yet. I did build mine with both the upper and lower ailerons which I believe will provide the best performance, but you may find someone who has only set theirs up with 2, and they should be able to help you more, and offer better advice. Good luck with the build! I sure enjoyed building mine! I also want to add that IMO a 2 stroke just would not do the Hog Bipe justice! I am sure it would fly it fine, but for some reason I just think a Hog Bipe should have a 4 stroke on it! The O.S, Magnum, or Saito .91 4 stroke seems to be the engine of choice! I installed a Saito 1.00 on mine, but I am thinking of going ahead and putting a Magnum .91 4 stroke on it instead since the 1.00 mat be just a bit more than I really need, and may be better suited for a different project.