Stern-Drive Operation; Propeller Selection - ILMOR One-Drive Owner's Manual

3-1
Section 3

STERN-DRIVE OPERATION

This section of the Owner's Manual describes the procedures for proper
operation of the stern-drive.
Before you operate the One-Drive, read the following safety information
and review Safety on page 1-1.

PROPELLER SELECTION

The propeller converts the engine's power into the thrust needed to propel
the vessel. Careful selection of your propeller is very important to proper
vessel operation. Propellers are identified by two numbers, such as 15.75
× 20 left-hand and stainless steel propeller. In the number sequence, the
first number is the diameter of the propeller and the second is the pitch.
Left-hand is counterclockwise rotation for front propeller. Right-hand is
clockwise rotation for rear propeller.
Pitch is the angle of the blades expressed in the theoretical distance a
propeller travels in each revolution. If for example the pitch is 20, each
revolution of the propeller pushes the vessel 20 in. through the water. A 28
pitch is considered "higher" pitched and a 20 pitch propeller is considered
"lower" pitched. A smaller pitch propeller should be selected for water
skiing or for heavy loads.
Keep these guidelines in mind when selecting a propeller:
• Your Ilmor Marine dealer or distributor is most qualified to help you
select a propeller.
NOTICE: Never attempt to change propellers until after determining the
average load and individual requirements.
• Engine rpm must be within the recommended operating range. Refer to
the Engine Operator's Manual.
WARNING! To prevent accidental start-up, complete the following
before installing or removing the propeller:
• Put the remote control to the NEUTRAL position.
• Put the main switch to the OFF position and remove the key.
WARNING! Never use your hand to hold the propeller when
loosening the nut. Put a wood block between the antiventilation
plate and the propeller blade to prevent the propeller from turning.
© 6/2016 Ilmor Marine Engines, Version 1.0