I love everything about round engines... the looks, the sounds... and this one runs very sweetly.
Here is a video of a cold start.
I am running a Xoar 36" X 12" Propeller. Fuel is 100 octane unleaded with a 40:1 mix of Amsoil synthetic 2 stroke racing oil. The engine has had about 2 gallons of fuel ran through it. Breakin was made with 91 octane unleaded (no ethanol), and a 32:1 mix of the same 2 stroke oil. Weight of the engine is about 15 lbs., and it produces about 16 hp. Idle RPM is 700 to 800. Full throttle is 5,700 RPM on the bench. I will probably go with a higher pitch prop to keep full throttle RPM around 5,500.
My intention is to fly this on the front of a 30% scale Balsa USA Stearman. It should be perfect.