2007 Evinrude E-Tec 75, 90 HP outboards Service Manual, Page 64Get this manual
INSTALLATION AND PREDELIVERY PROPELLERS
PROPELLERS
Propeller Selection
CAUTION
Selection of the wrong propeller could reduce engine service life, affect boat performance, or cause serious damage to the powerheadWater testing with various propeller designs and sizes is the best method of propeller selectionThe correct propeller, under normal load conditions, will allow the engine to run near the midpoint of the RPM operating range at full throttleRefer to TECHNICAL DATA on p18
When selecting propeller, consider the following: Use an accurate tachometer to determine the engine's full-throttle RPM The outboard should be trimmed for top speed Select propeller that suits the customer's application and allows the engine to run near the midpoint of the full-throttle operating range when the boat has normal load Occasionally, one propeller will not cover wide range of boat applications water skiing to high speed performance boatingIn such cases, it might be necessary to have propeller for each situation Refer to the EvinrudeJohnson Genuine Parts and Accessories Catalog for propeller styles and sizes Right-hand propellers are considered standard rotation propellersWhen propelling boat forward, the propeller rotates in right-hand (clockwise) direction as viewed from the rear Left-hand propellers are considered counterrotation propellersWhen propelling boat forward, the propeller rotates in left-hand (counterclockwise) direction as viewed from the rear