My 1979 9.2A 2qm15 powered came with a 2 blade Michigan Sailor I think RH 16 dia 8 inch pith. I replaced it with a three blade Campbell Sailor R-14-8. I get to 6 knots motoring in flat conditions with less vibration. Backing is smoother with less prop walk.
I do get some black exhaust at full throttle, a sign of overloading the engine. But, at about 3/4 throttle, the engine purrs, does not overheat and does nto smoke. I'm quite happy with this prop.