- Joined
- Apr 27, 2010
- Location
- Bethlehem, Georgia
Consult the engine owner’s manual to find the recommended wide-open-throttle (WOT) range for your engine. If the current propeller is at WOT RPM within the specified RPM range, select a replacement or upgrade propeller with the same pitch as the current propeller.
If the current propeller isn’t at WOT RPM within the recommended RPM range, select a replacement or upgrade propeller with a larger or smaller pitch using the following rules:
Adding 1 inch of propeller pitch will reduce WOT RPM by 150 to 200.
Subtracting 1 inch of propeller pitch will increase WOT by 150 to 200.
If you’re upgrading from a three blade to a four blade propeller, remember that a four blade propeller generally turns 50 to 100 RPM less than a three blade prop with the same pitch.
From the Mercury website http://www.mercurymarine.com/service-and-support/storage-and-maintenance/faqs/propellers/#Elevation
If the current propeller isn’t at WOT RPM within the recommended RPM range, select a replacement or upgrade propeller with a larger or smaller pitch using the following rules:
Adding 1 inch of propeller pitch will reduce WOT RPM by 150 to 200.
Subtracting 1 inch of propeller pitch will increase WOT by 150 to 200.
If you’re upgrading from a three blade to a four blade propeller, remember that a four blade propeller generally turns 50 to 100 RPM less than a three blade prop with the same pitch.
From the Mercury website http://www.mercurymarine.com/service-and-support/storage-and-maintenance/faqs/propellers/#Elevation