Propeller Selection
Selection of the wrong propeller could reduce engine service life, affect boat performance, or cause serious damage to the powerhead.
Water testing with various propeller designs and sizes is the best method of propeller selection.
The correct propeller, under normal load conditions, will allow the engine to run near the mid point of the RPM operating range at full throttle. Refer to SERVICE SPECIFICATIONS on p. 10.
- Percentage of horsepower
- Engine RPM
- Horsepower curve
- Full throttle operating range
- Midpoint of full throttle operating range
- Engine is overloaded at full throttle
- Engine is overspeeding at full throttle
IMPORTANT: If the propeller blades have too much pitch, the engine will operate below its nor mal range at full throttle. Power will be lost, and powerhead damage could occur. If the propeller blades have too little pitch, the engine will operate above its normal range and damage from over speeding could occur.
When selecting a 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 a 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 a normal load.
- Occasionally, one propeller will not cover a wide range of boat applications — water skiing to high speed performance boating. In such cases, it might be necessary to have a propeller for each situation.
- Refer to the Evinrude/Johnson Genuine Parts and Accessories Catalog for propeller styles and sizes.
Propeller Hardware Installation
When servicing the propeller, always shift the outboard to NEUTRAL, turn the key switch OFF, and twist and remove all spark plug leads so the engine cannot be started accidentally.
Apply Triple-Guard grease to the entire propeller shaft before installing the propeller.
Install thrust washer onto shaft with fishline trap groove facing forward. Taper of bushing must match taper of propeller shaft.
Install propeller on propeller shaft by aligning splines and pushing until seated on the thrust bushing.
IMPORTANT: Depending on propeller style, different thrust bushings, spacers, and cotter pin keepers are used. See the Evinrude/Johnson Genuine Parts book for a complete listing and descriptions.
Install the spacer, engaging the propeller shaft splines.
- Thrust bushing
- Spacer
- Propeller Nut
- Cotter pin
Wedge a block of wood between propeller blade and the anti-ventilation plate.
Install the propeller nut and tighten to a torque of:
- 120 to 144 in. lbs. (13.5 to 16.5 N·m)
If cotter pin holes in the propeller nut and propeller shaft are not aligned, tighten the nut until they are in line. Do not loosen.
Insert a new cotter pin through the propeller nut and shaft. Bend its ends over the nut to secure the assembly.
IMPORTANT: After fastening propeller nut, make sure outboard is in NEUTRAL and carefully spin propeller. Propeller must turn freely and should not spin off center. If propeller appears to wobble, check for possible bent propeller shaft.
