I have the Focus II with the Syssa SAP 180 gasser, and it is indeed a viable gas option for pattern. MattK and Ed Alt did the preliminary testing with pattern props, supplying the first actual RPM and thrust numbers. They looked good, so since I had been looking for just such an engine, I ordered one right away.

I did not make a mistake. My engine is far from being broken in and well-tuned, but already it has plenty of useful power with an APC 18x10PN... just a matter of tuning and prop selection. But even so, after very little tuning and break-in, it has plenty of power for a 10.5 lb pattern model.