Please note that the PICTURE UPLOAD function is not working. The iBoats Forum Moderators are working with the system administration folks at the parent company to get the issue resolved. This happened about a year ago and here we are again. In the meantime you can post photos as links to a picture hosting site of your choice. We are sorry about the inconvenience and will advise when the issue is resolved. Thank you for your patience.
If it was an OEM OMC, yes, the 13 spline hub, but diameter can range from 12-3/4 to 14" on this engine.
13.25 diam would be a 17P, 13 diam is 19P and 13-3/4 is a 15P
The 14" diam can be 13-19P.
What boat do you have?
You have a problem if that is all the information you have. The only way reasonable from there is to find a prop supplier who will allow you to try multiple props until you find the correct match. I would take a WAG at a 13 x19 based on the power and boat description as a starting point. You will need to run Wide Open Throttle tests to find out if the engine reaches rated rpm with each prop you try.
