Fuel Senders; Fuel Filters - Four winns 338 Vista Owner's Manual

E. Fuel Gauge
The fuel gauge indicates the amount of fuel in the fuel
tank. See Section E-9F - Fuel Gauge for additional
information on fuel gauge use.
F. Fuel Senders
The fuel sender consists of a float which travels up
and down a stationary tube. The float measures the
level of the fuel in the tank and sends a signal to the
fuel gauge. See Figure I5.
Figure I5: Fuel Sender Operation
Due to the mechanical nature of the fuel sender, varia-
tions in readings during various speeds of operation
may occur. This system is merely a relative indication
of the avail able fuel supply and not a calibrated
instru ment. With this type of sending unit a more
accurate measurement of fuel level is obtained with
the boat in a level position.
The gauge readings will also vary with the trim angle
of the boat. When sitting at a dock and the boat is
nearly level, the fuel gauge will register accurately.
Refer to Figure I3. When boating, the trim angle of the
boat changes and affects the gauge readings. Under
these conditions, the fuel sender will register "full" for
the first few hours of running time until the fuel level
drops below the 3/4 or 1/2 mark. This is caused by the
angle of the fuel in the tank as shown in Figure I6.
Figure I6: Effects of Trim Angle
It is very important to keep track of hours and fuel
consumption to obtain an average gallon per hour
consumption figure. Refer to the fuel log located at the
back of this manual. This will prevent any prob lems
with running out of fuel on the water.
Fuel Systems - Section I
Dealers are equipped with some general figures on
consumption which can be used as a guide until
specific information on your boat is deter mined.
Because of boating conditions, speed, weight and
other factors common to your situa tion, fuel consump-
tion will vary between your boat and consumption
figures developed by Four Winns.
When the fuel gauge begins to register below the "full"
mark, the gauge readings will drop much faster until it
reads" empty". When this occurs, the trim angle has
affected the sender reading. When the gauge regis-
ters "empty", the sender has bot tomed out and there
may be 3 to 4 gal lons of fuel in the tank.
See Figure I7.
Figure I7: Trim Angle Effect with Low Fuel
G. Fuel Filters
Fuel filters are installed on each engine. Filters should
changed frequently to assure an ade quate supply of
fuel to the engine. Refer to the engine manual for
additional infor ma tion. The engine manual is included
in the owner's information packet.
NOTICE
Canister-type filters should be changed
annually.
H. Gas Vapor Detector
A gas vapor detector is available on the 338 Vista®
models. The gas vapor detector will moni tor the
engine compartment and notify the operator of an
accumula tion of gasoline vapo rs. The operator must
take immediate action upon warning to avoid the
possibili ty of an explo sion.
The sensing unit is usually mounted towards the rear
of the engine compartment. The alarm unit is mounted
at the dash.
Owner's Manual Page 85