I currently have the Tohatsu 5hp outboard on my Potter 19. Maxes out at about 5-6 knots. Do you think I upgrade to a Merc 9.9hp (same physical weight as my Tohatsu 5HP) and get a few more knots out of her? Fighting the current around the Puget Sound will become a problem at some point considering where my available boat launches are. Some of the narrows can get to 5 knots.