Look at the Parker performance sheet for your boat and motor. That's what the motor should do. When boats are stored on the dealer's lot, they often remove props to prevent theft. When they sell the boat, they put a prop back on - the right one? Maybe. See what prop you have and then check with Parker to see what is right for your boat. I'm on my second Parker and both were propped wrong on delivery. My first Parker was a boat show display model. They removed the lower gearbox to display the boat. Later on, when we got the props right, both performed as advertised.