Took the boat out this evening for a test run with the demo prop. Failed my test. The 115 could spin that 13 7/8 x 19 OMC Viper upwards of 5800. Not good. Top end for a few seconds was only 45. Got home and scrubbed the heck out of the hub behind the nut with a stainless bristle brush and when tilted just the right way, I found the size of the factory OMC SST prop. It's 12 3/4 x 21.
FINALLY brought the camera and snapped a few pics as the sun was dropping.