Re: prop size
It would certainly help to know what boat you have, what prop you currently have, what the current wide open throttle rpm is and what the top speed is at that rpm. 17 and 19P are certainly in the ballpark, but why by two props to find out which one works best. Without the information above, its a crap shoot as to which one is best. Who knows -- a 21P may be in order, or 13 if the engine happens to be on a pontoon.