Roamad, it is the pitch on the prop, not the motor.
SSOBOL has a 13 1/2" diameter prop. The pitch is 15". In other words, one rotation of the prop and the prop travels 15" forward. The diameter and pitch should be stamped on the prop that you have. As has been discussed look at your owners manual and it will most likely tell you what rpm your motor should reach at Wide Open Throttle, WOT. I know that most of us do not run our C-Dory at WOT, but you want to be able to determine if you have the correct prop by doing so. If you don't know if your motor is propped correctly, pick a flat water day and operate at WOT with an average load that you run on your boat.