Hello, This is my first post. I am trying to figure out what prop to use with my 2186 Fish sweet water. I have the 115 SHO 20" shaft. Dealer put on 13-1/2 x12 pitch prop and it bounces off Rev limiter with 2 people full of fuel. Has a top speed of 26.8 MPH. Went back to dealer and put on 13-1/2 x15 And rpms dropped to 5750…