CONTINUOUSWAVE

"Who would think it could be so complicated?"
Thank you for the useful, detailed information.

Here is the test data from my 1989 15 Super Sport Limited with a 2006 Honda BF50 four-stroke and aluminum 11 x 17 propeller. Aboard were two people and 18-gallons of gassolin on board. Whaler engine performance data MPH RPM 3 950 5 1600 10 3000 15 3500 20 3800 25 4250 26 4400 (WOT) I'm looki...

SOLD! Thanks to Continuous Wave. 1989 Mercury 60 HP 2-stroke outboard with harness and controls. Power tilt/trim, electric start, SS prop and spare aluminum prop, anti-cavitation plate. Pushed my 15' Whaler up to 36 MPH. Recent lower unit service, seals,and overall tune-up by certified mechanic was ...

15'. No luck finding a prop shop with a trial-and-error prop lending program.
The Outboard Motor Shop in Oakland, CA, calculated a 17 inch pitch. That's the same scientific-wild-a$$-guess I came up with. I ordered one and am waiting to try it out.

Great thread; looking for a slightly different "twist": I've got an 89 SuperSport Limited. I just replaced the 60 HP Merc 2-stroke with a 2006 Honda BF50 50 HP 4-stroke. The prop is 11 3/4 x 10. The Merc had no tach, but would push the boat at 36 mph at wide open throttle. Nice. The Honda ...

I have a [1989] Super Sport Limited. I just replaced the Mercury 60-HP engine with a 2006 Honda BF50. The propeller is 11 3/4 x 10. The Mercury [60-HP engine] had no tach; its best boat speed was 36-MPH at wide open throttle. The Honda [50-HP engine accelerates] to the limiter at 6,500-RPM before [t...