Thanks Frazier, How did you fix the prop to the shaft? I have been thinking about this as I know the full sized boats usually have a tapered shaft with keyway and end nut but that would be difficult on our size shafts I am thinking. I too am making the prop to the direction of the best rotation of the engine. It runs on no load at 5 psi clockwise and 7 psi anticlockwise. I am assuming this is to do with the timing and valve openings, but I am happy enough with it as it will not be going too far astern.
Robert