Does any one know a way to slow down a mercury 150 going in reverse? Have a slip that I have to back into and my boat is too fast all the time. [/quote
I used a drift sock clipped on the eye.
Had a 150 Suzuki, worked pretty good
If it seems abnormally fast it might be worth making sure your idle speed is to spec.
For actual backtrolling (not just backing) a four blade prop is slightly slower in reverse, a five blade is really slow. The more blades you have the less reverse thrust you have due to cavitation, but lose maneuverability.