My second engine was a 4-stroke, an O.S. 91 Surpass. They are no harder to tune than a 2-stroke, like Richard L. said they have the same adjustments. I use 4-strokes on everything, except my giant scale (2-stroke gassers). I doubt I will ever buy another 2-stroke. The argument about 2-strokes being lighter and more powerful doesn't hold that much weight anymore. My Saito 82a 4-stroke is as light as any .46 2-stroke and swings a 14" prop at 9000 rpm. That's light weight with lots of power! If you want speed take a look at the YS. Richard L. runs YS 63's in his warbirds and will attest to their performance. In my opinion, for an aerobat such as your Edge, a 4-stroke is the best choice. Good luck!