I notice that no one mentioned the ASP Super Series. I bought a ASP 52 Super Series myself to try out. I am using it to replace an 40FX on my Tiger2. Not that the OS engine didn't fly the plane well, just looking for more punch. The 52 looks like an OS clone but haven't had a chance to try it. The carb barrel turns smooth as silk just like an OS. Might be another engine to check out. Still too much mud and snow to get to our field and try mine. [8D]