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Figure B1: Stern Drive
Consult the Engine Owners manual for additional informa-
tion on stern drives.
B - 4
ENGINE FLUSHING
The engine flush out option is offered on all Vista models.
The engine flushing kits attach permanently to the en-
gine. A fresh water supply can be connected to the en-
gine with the boat in the water. It is not intended for use
with the boat out of the water. This option is useful to
flush the engine cooling system of unwanted salt resi-
due.
The flush out kit should only be used with the boat in the
water and the engine OFF. See Section O General Main-
tenance for flushing procedures.
B - 5
PROPELLERS
Knowledge of the propeller is most easily gained through
better understanding of the terminology used to refer to
the aspects of propeller size and performance.
A. Diameter
Diameter is twice the distance from the center of the prop
shaft to the extreme tip of a propeller blade. Increasing or
decreasing propeller size will have a direct bearing on the
RPM's an engine will develop. This is due to the greater
amount of propeller blade surface in contact with the wa-
ter. See Figure B2.
Vista Owners Manual
10/93
Figure B2: Propeller Pitch & Diameter
B. Pitch
Pitch is a measure of helix angle, or angle of attack, of
the rotating blade. Pitch is easily understood if one imag-
ines the propeller rotating through a semi-solid such as
butter or gelatin. The distance the propeller will travel in
one revolution is called "Pitch." Increasing or decreasing
pitch will also have a direct bearing on engine RPM's
because of the greater bite taken by the blade with each
rotation. See Figure B2.
C. Prop Slip
When traveling through water a propeller is unable to get
a complete bite because of the fluidity of water. "Prop
Slip" is usually expressed as a percent of the computed
theoretical speed. Twentyfive to thirty-five percent prop
Section B
Page 4
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