Follow the instructions! It will come out right as the offset is built in, trust me I have done two UCD's. The 46 is really going to be lacking on this plane and you may need a fuel regulator to keep from flooding out the engine as the tank is too high and can cause this problem. You will like the plane when you get it dialed. I tried a 61 2 stroke and it was not enough, I now have a 91 Mag FS with a Ironbay regulator, sweet setup.