I got everything put together finally, and ran the engine yesterday morning, before the weather turned nasty here in the NE. Initial impressions and thoughts are as follows:

First off, WOW. This is definitely viable for Pattern. As smooth a runner as the Webra 160 I believe. Lots of useful power in the rpm range we need

The rubber isolation mount described here-in works as well as I expected. Eventhough it is lightweight, it held up fine. To be certain, I need another couple hours of running to make the full assessment, but after 3 runs, everything is a GO. Very little vibration was noticed at all throttle settings, and even without a nose ring, the prop showed practically no sideways movement or wobble. I may forgo adding a ring to the nose.... but, we'll see!!

Engine turned out to be easy to start once I figured out what I was doing wrong. Even with the engine brand new and not broken in, throttleability is better than the Webra and appears to be on par with the YS engines I have run. Idle is superb and with this soft mount, very controlled in terms of vibration. Very smooth transition with a full, throaty sound at full revs. There is very little noise at idle and mid rpms.... I can imagine a model in downwind leg at partial throttle sounding very stealthy. At full revs, the engine makes some noise and I need to figure out how to reduce that. Intake seems to make much of that noise so that should be straight forward to control.

Some of the particulars of the set-up:

The Pipe I used is the large ES carbon pipe intended for the Webra 160. It isn't the one Ed Skorepa makes specifically for this engine. I don't think there will be a need to buy the new pipe, unless he does something totally different for gas compared to fuel for his pipes. Gasoline exhaust gets a little hotter and gasoline has different solvent characteristics than alcohol, so the epoxy he uses might be different, but I don't know that right now. I'll tell you this... the pipe cooled down very quickly after runs were finished; quicker than the header and aluminum header extension I used. The ally header extension is a simple 8" length from a broom handle, attached with silicone rubber at both ends. Silicone rubber and gasoline don't mix as well as silicone and fuel do, but for now, it will do. Ideally, a longer header will be welded to avoid some of the problem

I set the first reflector baffle at 27" from the exhaust flange, straight line (didn't follow the curve of the header) to the fiirst baffle. The prop is the ZDZ 20x10 for initial runs. I also have a 20-12 on hand. Talking with Dean Pappas about it last night at dinner, he suggested for Pattern type speed something like a 19x14. Even with the 20x10, the full revs noise level was similar to that my Webra 160 makes but I didn't measure it. RPMs at full throttle sounded like 7K, maybe 7.2K. That's very useful if not a bit noisy with a 20" diameter
prop. More pitch and smaller diameter will reduce the prop noise a bit.

The battery I used is a 2 cell Li-Ion that I had laying around from an old camera. It's a 2000mah, 8.4 volt set-up (at full charge).

The spark sensor was set at the factory setting and worked well there.

The Walbro carb was set at the factory pretty much. I needed to adjust the low speed needle and just barely touched the hi speed needle. The final settings after running the engine were low speed open 1 1/2 turns and hi speed open 1 1/16 turn. Low speed needle was leaned out about 1/4 turn and hi speed richened about 1/16th. I could see just a bit of smoke. For flying, the factory settings could probably work fine.

An interesting aside regards to flying a gassie like this one, these beasties do not smoke like the standard fuel powerplants do, especially the YS 160-170 engines. Some top level competitors who are flying YS have expressed concern about the smoke trail. Well, this could be an answer to that issue. We'll see how things develop.

I will post some pictures in the next post

MattK