Russ, I find this info very interesting. In fact, I thank Smitty very much for bringing you into this thread and all the information you have provided that could not come from anywhere else. With all your wealth of knowledge you might see a but coming, and there is. Your vast knowledge of two cycles as you say was of motorcycles, but you played around with Jim on his outboard motor stuff. I have corresponded (not lately) with an English motorcycle guy that wants information regarding the first use of rotary valve engines. He wanted to know if Dieter Konig's rotary valve engines were a result of what a guy named Zimmerman in East Berlin did, or if it was a separate development. Zimmerman was a motorcycle guy, and had been working on rotary valves for motorcycles before Deiter. I don't want to hijack this excellent thread, but I know you don't go anywhere else, so I figured this was the only place I could ask this question. If you want to respond, you can PM me or answer me here and we will set up a separate thread to hear your input and not take away or get sidetracked from this excellent thread on Jim Hallum. If you don't want to, that's OK. I thank Smitty very much for bringing you to this forum in the first place and all the history you have given us.