Hi all,

The number is SSO-515-II-C and it is supposed to be a Michigan Wheel.

I tried the Michigan website, no luck.

Here is what I do know, I have an OMC 391198 13.75 X 15 aluminum
and the engine ran exactly 5000rpm w.o.t.
This Michigan stainless prop was in a box marked 13.75 X 15 stainless.
When I installed this stainless prop, my w.o.t. went to 6000rpm. That
makes no sense at all!! I would say the prop behaves like a 13 pitch
or even an 11 pitch. The boat holeshots like a rocket, and although
I don't have a speedometer, the boat does seem a tiny bit slower at
the original 5000rpm line.

This prop is about 10 years old dealer stock. Did someone put the wrong
prop in the box?? It really does look very much like 13.75 X 15 from
all I can measure. What is going on here?

Thanks!