Hi Folks, I'm the one who originally put the OS .26 on Pat Johnston's Ringmaster. I got the plane from him and it had an FP .25 on it. It flew okay, but I wanted to try the little OS .26 four stroke. I got the manifold reworked by Bob Zambelli and it worked flawlessly from day one. I used a Perfect 2 ounce fuel tank, changed the fill tube out so it pointed forward, used muffler pressure, 10 X 6 Top Flite wide blade prop and flew on 62 foot lines. It was very nose heavy, but after I learned how to do a good landing when the engine stopped, the nose heavy condition did not hurt anything. I tried adding tail weight at one time, but plane did not fly as well. It weighed 27 ounces with the .26, 25 ounces with the FP .25.
Pat built the plane and it was very light, monokote on the wing an tail, Rustoleum on the fuse. The only realy change I did to the thing along the way was to put a 1/32" wire between the landing gear legs, they were 3/32" and a bit springy. But, the secret to getting a good landing was to be close to the ground when the engine stopped and get it on the ground ASAP, no down elevator, just hold neutral. John Thompson has the plane now and is having as much fun with it as I did.
I started out running SIG fuel with Castor oil in it, as time went on the engine started running ratty, at this time I noticed that everyone was using Power Master 4 stroke fuel, so I changed to it. The fuel cleaned the valves off and it started running fine again. Thanks to Bob Reeves and Bob Zambelli for making 4 stroke flying fun. Wish they still made the OS .26 four stroke they are so good.