Did you ever see a 3 ring RC engine. Well here is a photo of the one that I have. I don't remember the displacement but it will turn an 18x10 prop about the same as a G-38. It starts very easy by hand and is about the smoothest single that I've run. I think this is due to the fact that it is well balanced and weighs 7 pounds. It uses points and is called a Kioritz. Compression is great. I believe the original use was as a backpack blower. They were popular in the late 70s and early 80s.