RE: OS SX 50
I agree the 12.25 3.75 apc is the best for this engine, i have one in a flip 3D with a hatori 540 pipe. Blistering perfomance with this prop. (13,540 RPM)I have found that my engine has taken a long time to run in properly ( 3 gal) of 5% Synth to get it perfect,
Andy