I broke a Magnum 91 4-stroke into 4 pieces when the plane crashed full-throttle into the woods after the RX battery went out of juice. It was partially my fault because I decided to take *just one more* flight. This was the 2nd Sunday since it was charged, and 6th flight of that day. Anyway, I was lucky that it crashed into the woods instead of something valuable. I stripped 1 servo out of 7, not bad! The engine's crankcase split right in half, the overhead valve assy broke off, carb broke off, and of course, the muffler came off. I was able to sell the muffler for $12, because it was still in perfect shape.