I have 2 of these mounted in 73” 3D aircraft. For my particular style of flying, these both provide PLENTY of power on the recommended break-in prop.
Vertical is unlimited, pulls outa hovers nicely, and transitions perfectly. Starting is a bit tricky, as these will start AND run backwards. I’m left handed, so I squat on the right side of the aircraft and pull the prop through from underneath. If I don’t pull completely through, she’ll fire n run backwards, which I didn’t think could happen, but it does.
Choke, ign OFF, pull the prop though a couple times, ign ON, she’ll fire on the second flip. Ya gotta flip the prop through all the way!. Choke off, 2-3 flips and she fires right up. A pinch fat on the top end for break-in, and let er rip. This engine is strong, reliable, and responsive. I’m actually amazed at the compression I’m seeing before I have the engine even broke in.
One thing that is puzzling me though, I have “blown out” 2 after market Pitts style muffs. One muffler failed at the apex of the 90° weld, and the other split the muffler can apart from the header flange, like cracking an egg???? If this is a vibration issue, well, I’m gonna find out. I’ll mount the stock single tube Pitts muffler and wring it out. If I have any more failures, I’ll be sure to post that update. I don’t have any reason to believe that the engine or prop are THAT out of balance. But blowing out 2 muffs on the same engine is a bit questionable.
