Dunno what it is, but it sure looks like an East European combat .15. Bet it hauls that poor little Ringmaster around faster than it ought to go!

 Both wrong. It's not a Combat .15 and not eastern made, But you are correct Ralph the Ringmaster was not made to go that fast.     Martin you are way off, this is a new engine.
 The engine is a Brazillian CB .25. It swings that 10/5 prop at close to 11,000 RPM. On 58 ft. lines it tries to screw you into the ground. That little engine weighs in at 6.4 ozs. The tank is 3.5 ozs and it seems like an eternity before it runs dry.
 Has an hour of run time and gets better every flight.

  "Billy G"  

Bill I was just joking

 it's me Martin your "translator" @ Brodaks when you got the engine remember? 

cheers,

Martin

  Yes Martin, I remember you very well. I was joking also. I knew you knew what it was. This little jewel is a rare bear indeed. I thank you and Elizio for getting it for me. Now I wish I had bought the other one too. Tell Elizio this is one heck of an engine.

  "Billy G"