I have a 1993 18ft ski boat witn a 230B. When I bought the boat it had a 15X19 broken prop on it. I bought a 13 X 15 used and tryed it. The boat didn't plane out well and the RPMs were high at full speed, I blamed the prop and bought a new 15X19. Now it is ten times worse. It will not plane out at all. Is this a prop issue or could it be performance related? I also tried it with and without a "whale tail". Please help before it I send it to the bottom of the lake.