Operation Of The Injection System; Oil Injection System - Mercury 45 Jet 50-55 Service Manual

Operation of the Injection
System
The oil injection system delivers a oil mixture thru a con-
stant ratio oil pump.
The engine mounted oil reservoir holds 3 qts. (2.8 Liters)
which will provide 10.5 hours of running time at wide open
throttle.
A low oil warning horn will be activated when 14.5 fl. oz.
(435 ml) of oil remains in the reservoir. This will provide ap-
proximately 1.5 hours of wide open throttle running before
oil is depleted.
The crankshaft driven oil pump injects oil into the fuel be-
fore the fuel pump.

Oil Injection System

1. Oil Reservoir
The oil reservoir gravity feeds oil to the oil pump. The
reservoir contains a low oil sensor which activates a
warning horn when 14.5 fl. oz. (435 ml) of oil remains
in the reservoir.
90-817643R1 DECEMBER 1996
2. Oil Injection Pump
The crankshaft driven oil pump is a constant ratio oil
pump which provides an oil fuel mixture.
3. Check Valve Vent
Provides air to oil reservoir for proper venting and also
prevents oil leaks when outboard is tilted forward.
4. 2 PSI Check Valve
This valve prevents gasoline from being forced into oil
line.
5. Low Oil Sensor
When oil level in reservoir drops to approximately 14.5
fl. oz. (435 ml), the sensor will signal warning module
to activate warning horn.
6. Warning Module
When ignition key is initially turned on, the warning
module will briefly provide a self test of its engine over-
heat warning system - a brief continuous BEEP tone,
followed by a self test of its low oil warning system - a
brief intermittent BEEP-BEEP tone.
If the oil in the reservoir drops to less than 14.5 fl. oz. (435
ml), the low oil sensor in the reservoir will signal the warn-
ing module to activate the warning horn. If the powerhead
temperature should exceed 300 F (65 C), the overheat
temperature sensor in the water jacket cover will signal the
warning module to activate the warning horn.
FUEL SYSTEMS - 3D-1