ORIGINAL: PlaneKrazee
Bterry,
There was something wrong with your OS!. Both of mine and a fellow club members spun a APC 18X6 over 9200 on 5% nitro with stock exhaust. The Mejzlik would spin 10000 rpm on 15%!
The OS does make 3.7hp and the Syssa makes 3.0hp after 2 gallons which must be over 6 hours of run time.
The engine on the BCM muffler never impressed me. The muffler was very nice, and built very well, but the engine just didn't run very well on it. The engine definitely runs best on the stock exhaust.
Now that I think about it a bit more it was probably a mejlik 18x8. I had the APC 18x6w on the engine, and I think I was confused with that. I only tried it that one day, and like I said it was mid-80's and maybe 95% humidity.
p.s. I spent a lot of time working in Groton, and stayed in Mystic, CT. I went to the field just over the border into RI (off I-95) a few times. I think it is very in or near Westerly. Maybe I met you?! Incidentally my OS was in a GP Soucy Extra 300S - I think you had one of those too. The Syssa engine would be PERFECT in a plane like that!