What Prop?

[Fr. Frank]

Originally Posted by McGillicuddy

Jorge,
You prop appears to be an older Yamaha semi-cleaver

That's exactly what it is, Jorge. The 17-M series props are the early Yamaha salt-water props, and provide as much stern lift at high RPMs as the Mercury Mirage. Their weakness is in a reduced rake progression on the outer 1/3 of the blade, which gives them great top-end performance, but weakening their mid-range performance. They run very well as a semi-surfacing prop for WOT/high-rpm performance, with slip ratios that can be down around 8%, but have higher 15%+ slip ratios at greater running depths, at mid-range RPMs.