P
E R F O R M A N C E
4–1
C h a p t e r 4 : P e r f o r m a n c e
P
ERFORMANCE
F
ACTORS
Maximum performance is dependent on many factors and cannot be guaranteed. These factors
will vary with changing conditions. Some of these factors are listed below. Reference the trouble-
shooting guide on page 65 in
Sportfish, Cruisers, Yachts Owner’s Manual
for additional
suggestions on adjusting performance.
Engine Efficiency
Engines operate most efficiently when they are properly tuned, and the props are in good
condition. Efficiency will decrease if normal care and maintenance is not performed.
Neglecting the engines will cause power to drop and speed to decrease. In addition, expensive
repairs may become necessary. Be sure to follow all instructions in the engine operation
manual(s).
Weather Conditions
Weather conditions sway engine performance. Barometric pressure and humidity affect
horsepower. A change of weather could amount to a 10% loss in horsepower on some hot
days.
Load Distribution
A decrease in performance will be noted when gear, equipment, passengers, and fuel are
added. This extra load will affect the performance of your boat according to the distribution of
the weight. Another type of extra load that could affect performance is the accumulation of
water in the bilge. Keep the bilge dry to eliminate this type problem.
Marine Growth
Maximum performance is obtained only when your hull bottom is clean. Marine growth on
the bottom of the boat will increase resistance and decrease speed. These conditions will also
increase fuel consumption. Reference
“Cleaning” on page 6–1
for more information on
cleaning your hull bottom.
Trim
The outboard engines are equipped with power tilt and trim mechanisms. The purpose of
power tilt is to raise the engine(s) for launching, loading or trailering. Power trim may be
used to adjust the boat’s planing performance and running attitude. See power trim, page 52
and 72, in
Sportfish, Cruisers, Yachts Owner’s Manual
.
Trim refers both to the weight distributions inside the boat and to the angle of thrust of the
engine. The angle of thrust of the engine forces the bow up or down. The trim tabs on your
boat also control the trim of the boat, similar to the power trim. Refer to the Trim Tabs section
in Chapter 8 for additional information.
