Hi guys. I saw this thread and just had to dig out my old pics of my "Hammer 40". This plane flew very well and I would rate it right up there along the Koas and the Kiwi which I also ran an OS .50 FSR on. I ran an OS .50 FSR with a pre-tunned pipe designed just for this engine. I had about 20 flights on it when it went in. I lost the plane in the sun straight out from me and thats all it takes. Sorry for the quality of the pics but they were very old and not in real good shape.