Now, determine your wide open throttle (WOT) RPM
For safety and efficient performance, it is critical that your engine operates within the RPM range recommended by the
manufacturer. Matching the right prop for the load is the most significant factor of RPM adjustment.
Effect of Prop Pitch on RPM
A pitch change can increase or decrease the RPM’s and
bring RPM’s into the recommended range. A 2" increase in
pitch (for example, from 21" to 23") typically results in a
decrease of approximately 300-400 RPM.
First, Determine Manufacturer’s
Recommended RPM
Find the manufacturer’s recommended RPM range in the
owner’s manual or ask your dealer.
Test for Maximum RPM
Using the existing propeller or a new propeller, make test
runs to determine the maximum RPM and boat speed. Vary
the trim angle for optimum performance.
RPM Higher Than Recommended
If the actual WOT RPM’s are above the recommended
RPM range, install the next larger pitch propeller to
decrease your WOT RPM. Re-test the WOT RPM.
RPM Lower Than Recommended
If the actual WOT RPM range is below the recommended
range, install the next smaller pitch propeller to increase
your WOT RPM. Re-test the WOT RPM.
