GOOD NEWS. . . . The PICTURE UPLOAD FUNCTION IS WORKING !!! The tech folks at the parent company have been able to remedy the issue. You can upload pictures once again. Thank you for your patience.
To do this accurately we need the present prop size(under the prop nut or near the base of the blades)
wot rpm and speed. An induction tach is easy to hook up and some cells have a gps app.
Also need year of motor.
Assuming that is a Lowe 1436, the Mercury prop selector comes up with a Vengeance SS 10.38 X13" pitch. I believe that is the "biggest" pitch prop Merc makes for that motor.
I know they make props for 2 stroke merc 25hp at least as big as a 10.125X15 not to say he can turn it at recommended RPM's though. Got no info to go off of.