Field Report: AWESOME!!! I want another one! I put the engine in a 40 size sport flier that formerly held an OS 55AX w/MACS muffler. Out of the box, this thing fired practically right up and maxed out at 13,300 RPMs on the ground w/10x6 APC prop. The idle and transition to full throttle was also flawless, with no need to mess with the low speed needle setting. I got 13,823 RPMs in the air. An electric starter worked wonderfully on this engine, just like a 2-stroker. Head temps got up to about 175*. I measured head temp and RPMs with the DX-8 telemetry system.

I got in two flights with the 10x6 and switched to an 11x7 APC for the third flight because the 10x6 was barely enough prop for the plane. The APC 11x7 worked much, much better at this altitude. The RPMs dropped to about 10,600 loaded and 13100 unloaded in the air, and the idle came down to about 2300. All total, I got about 21 minutes engine run time and it used approx. 4 oz gas. I'd flown more, but the winds picked up and were 60-80* across the runway. Except for setting the idle trim and the HS needle in the pits for the first 5-6 minutes, I was nearly full throttle the entire time in the air. I’d estimate the performance of this engine is on par with my OS 55AX, and that’s in the first ½ tank!

I used 91 octane "clean gas", with Pennzoil air cooled 2 cycle engine oil at the recommended 20:1 ratio. The Pikes Peak R/C Club airfield altitude is ~6700 ft, Air temp 39*, and the humidity was about 25%.

My only observation was that the muffler screws definitely needs Loctite and checked every flight. The skimpy O-rings on the muffler body are way too thin and do not do much for sealing out the black exhaust residue. I stopped by the local parts store and got thicker O-rings for the muffler body and hopefully that will keep the residue from leaking out around the center section.

Dave