Hey f2racer, I have a YS FZ63 four stroke engine in my Zero. The engine hauls ***** and sounds good doing it. At full throttle, the plane flies at 120+ mph and almost has unlimited vertical even though it weighs 7 lbs 1.8 oz. As you can see from the picture, I mounted the engine inverted, which resulted in a very nice and clean look. I had to cut away the shelf under the engine to make room for the cylinder head. I installed my battery pack under the fuel tank and had to add 7.5 oz of lead to the nose to get the plane to balance. Nevertheless, this is still one great flying plane.

I got my Zero from eBay too, and I was informed that my Zero is around two to three years old. The newer version will be significantly better in terms of quality. I already have another gray one on back order from Morris Hobbies.