Successful maiden flight of Smaragd powered by OS GT33 gas engine on a Hyde mount with Hatori header and Canister: After rain, our runway was not good for maiden flight; but weather was OK, 10 deg C (50 deg F), 50% humidity and some wind. Honeycomb light wall isolate the canister muffler from electronics and gas tank, photo attached.
To make sure idle setup checked again; video attached: http://www.youtube.com/watch?v=ke2sO_nC30w . Starting engine by hand crank was not easy and several back-ward starting. But very reliable idling on around 1950 RPM with 18x10 prop, not much vibration on a Hyde mount, and glow-like sound with Hatori header and canister muffler. Highest RPM reached up to 7670, no vibration on Hyde mount.
After several safe flights, engine sound was slightly changed to crackling, and could not stop the engine even with fully closed throttle. One of two bolts tightening the muffler header was missing. Does it make sense even fully closed throttle? I think it might be, air can get into through exhaust outlet, it is my first experience.
On a test bed, all OS GT33 engine with stock pitts style muffler and a stock gasket was working fine. I think based on several threads, engines mounted on planes with canister mufflers with other gasket in my case, Starting engine was not easy and even backward starting. Wide opening of throttle, more than 50%, resulted in successful forward starting, but it is dangerous. The stock gasket was good to tight the stock muffler, it is melted to fit on the muffler, it is difficult for reuse. I hope to buy it from Towerhobbies, but not in the parts list. I need a good gasket again.
I will post a video on high speed running gas engine on Hyde mount later after fixing the exhaust header fitting.
Regards