Four winns SL Series Owner's Manual page 57

Figure E5: Tachometer/Hour Meter Gauge
B. Speedometer
The speedometer is a water pressure sensitive unit.
It has a pick-up (pitot tube) assembly mount ed on the
transom and a small plastic hose (spee do tube) that
connects it to the speedome ter gauge on the dash.
See Figure E6. The pitot tube extends below the
hull. Water strikes the tube inlet and creates positive
pres sure. The faster the boat speed, the greater the
pres sure, and the higher the speed indica tion on the
speed ome ter.
Figure E6: Speedo Sender
If the pick-up becomes clogged, the speedometer will
not register. Clean the opening with a piece of wire
or disconnect the tubing and blow out the pick-up with
com pressed air.
When winterizing the boat, the speedometer tubing
must be drained of water. Disconnect the speed ome-
ter hose at the pick-up assembly and at the gauge
and blow through the tubing to remove the water.
NOTICE
Speedometers are not precision instru ments.
The indications are relative and should never
be used for navigational purposes or similar
critical situa tions.
Engines and Instrumentation - Section E
DO NOT rely on the speedometer when trying
to achieve a "NO WAKE" condition in a harbor
or other enclosed water way. ALWAYS reduce
throttle! Speed ometers are not effective at
mea suring low opera tional speeds. You are
responsible for damage caused by the wake
of your boat.
C. Temperature Gauge (4-in-1 Gauge)
The temperature gauge (included in the 4-in-1 gauge)
monitors the cooling system of the engine. A sudden
increase in water temperature could be a signal of a
blocked cooling passage or a water pump malfunc-
tion.
NOTICE
Operation of an over heat ed en gine can re sult
in en gine sei zure. If an un usu ally high tem-
pera ture read ing oc curs, shut the en gine off
im me di ately.
D. Oil Pressure Gauge (4-in-1 Gauge)
The oil pressure gauge (included in the 4-in-1 gauge)
indicates the pressure in the engine lubrication sys-
tem. A significant drop in oil pres sure is a possible
indication of an oil pump or other leak age problem.
The engine has been equipped with an audible engine
alarm, the alarm should sound if the oil pressure
drops below the normal operating range of the engine.
Please see your engine owner's manual for specific
engine information.
NOTICE
Operation of an engine with ab normal ly low oil
pressure can lead to engine dam age and pos-
sible seizure. Have the en gine ser viced imme-
diately upon a re duced oil pressure indication.
E. Voltmeter (4-in-1 Gauge)
The voltmeter (included in the 4-in-1 gauge) monitors
battery condition and thus alternator performance.
See Section H for addi tional information regarding
electrical systems.
Owner's Manual Page 54