Thanks for the response. I now have a just at two gallons through my NIB FT-120 Gemini II. It starts and runs great. My observation while flying it was that it seemed to lose a bit of power/rpm in flight. On the ground I tune the high speed needle to peak and then back it off about 400-500 rpm. This may be a bit much to back off but for now I'm trying to ensure it doesn't run lean. Anyway, if flight, the engine just sounds as if it were running a bit rich. It doesn't sound as if it develops the rpm that it does on the ground. The carb on this installation sticks out below the cowl and faces directly into the airstream. I know that absent wind tunnel testing, one could aerodynamically argue that the carb might go rich, lean or neither. I would imagine that since there are not a significant number of these engines in use and probably only a small number of those with the carb exposed that the experiences of others may be hard to come by. I probably should have posted this question in the glow forum, but I kinda thought a modeler aerodynamicst among us might have the answer. If, at this point, I had to pick an answer, I would say the effect, if any, was slight.