I just purchased a Bennington 20SLI Pontoon with the F70LA 4-stroke.
WOT RPM range 5300 to 6300, gear ratio 2.33 / 1.
It came with a Solas 4 blade 13x15 prop that would only get to 5000 RPM and 18+ MPH.
The Published Yamaha Performance Guide uses a Yamaha 13 5/8 x 13 prop which I
bought and...