Re: mercury v6 150hp black max
KCLOST is giving you the right #s, Its trial and error from there. Im running a 25P High Five on my 18' Bass boat with the same engine, but you are going to need a lower pitch, I think I would opt for a four blade in a stainless, probably a 21-23P.<br /><br />Where is you cavitation plate in reference to the bottom of your hull? Thats the plate above your prop on the outdrive. Put the engine about vertical and line up that plate with the bottom of the boat and let us know if it is even, lower, or higher and how much in inches.<br /><br />Have you run this engine on this boat before, or is it new to this boat?<br /><br />If you have run this engine, we need to know the Wide open throttle RPMs and what prop you are using now. The more information you can give us the better.