I would like to establish the ideal propeller pitch for my Chrysler 20 HP model 2003 circa 1969 that came originally with an 8 1/2" dia. X 8 1/2" pitch propeller and is now mounted on a Boston Whaler 11 Sport from 1986 which has a displacement of 560# considering that my motor could run at 5500 rpm at wide open throttle.<br />Is there a formula to get to the pitch of the propeller or do I have to run the boat and measure rpms?
