Running Of Engines In Idle; Altitude And Sea Conditions; Portable Generator Sets; Maintenance - Engine Performance - Four winns 248 Vista Owner's Manual

Q. Running of Engines in Idle
Engines running in idle exhaust carbon monoxide that
can accumulate near the hull of the boat. Do not stand
or swim near the engine exhaust or outdrive when en-
gines are idling or generator is running.
R. Altitude and Sea Conditions
Operation at altitudes greater than 5,000 feet contributes
to inefficient engine performance and may require ad-
justments to the ignition systems, fuel systems, or chang-
ing the propeller's size or gear ratio.
1. Failure to make adjustments to ignition systems and/
or fuel systems for altitude conditions may cause
an increase in CO production.
2. Reduced power resulting from increased altitude
may require adjustments to propeller size.
3. Heavy sea or out of trim conditions tend to load
engines resulting in reduced performance and
thereby increasing their CO production.
S. Portable Generator Sets
Never use a portable generator on a boat.
Gasoline powered portable generators are available in
the marine market place and are not an option available
through Four Winns. Portable generators will produce
CO. These sets discharge their exhaust products in lo-
cations which can lead to an increase in the accumula-
tion of carbon monoxide in the accommodation (occu-
pied) space. Do not use gasoline powered portable
generators on Four Winns® boats.
T. Maintenance - Engine Performance
Efficient engine performance is vital to minimizing CO
production. The following items are those considered to
have the greatest effect on increased CO production:
1. Fuel Systems - Fuel that is contaminated, stale or
incorrect octane number
2. Carburetors/Injectors
a. Dirty or clogged flame arrester
Vista™ Owner's Manual
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b. Malfunctioning automatic choke plate or faulty
adjustment of manual choke plate
c. Worn float needle valve and seat
d. High float level
e. Incorrect idle mixture adjustment
f. Dirty or worn injectors
3. Ignition System
a. Fouled or worn spark plug.
b. Worn points or incorrect gap on points
c. Shorted or opened circuit high tension spark plug
cables
d. Incorrect ignition timing.
4. General
a. Worn piston rings and valves
b. Engine temperature - Cold running engines in-
crease CO production. Engine cooling water
system design and selection of thermostat(s)
are primary considerations affecting engine op-
erating temperature. Generally, an engine pro-
duces less CO if it operates at a relatively high
temperature within manufacturer's specifica-
tions.
c. Exhaust Back-Pressure - Certain alterations to
the exhaust system may increase engine ex-
haust back pressure and CO production.
d. Restricted engine room or compartment venti-
lation
U. Maintenance - External Conditions
External conditions that contribute to inefficient engine
performance can include:
1. Fouled hull bottom
2. Damaged and fouled running gear (i.e., shaft, strut
propeller, rudder and trim tabs)
3. Incorrect selection of propeller size
Section B
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