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I have a 1986 13 foot Boston Whaler Super Sport with a 40 horsepower 4 stroke Mercury outboard that has a 2 to 1 ratio. What pitch and diameter prop should I install on the motor?

Thanks in advance for your input

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H -

Welcome to WhalerCentral.

Prop selection is a bit of science with a dash of art.

When discussing props, you have two material choices, aluminum or stainless steel. Generally speaking stainless is the recommended choice.

Prop size is not universal across brands or even between models. This means if someone says a 13" pitch in model X, that same size may not perform the same in model y.

For these reasons, we try to offer specific brand and model and size suggestions for your model of boat with a Mercury 40 hp Fourstroke.

I would start with a Mercury Spitfire 10.1 x 14.

Target wide open throttle would be ~5400 mph and 32 mph running solo and light.