1997+ Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-826148R2, Page 165Get this manual
Theory of Operation The oil injection system delivers oil mixture thru variable ratio oil pumpThe engine mounted oil reservoir holds 50.5 (1.5 Liters) which will provide 4.5 hours of running time at wide open throttleA low oil warning horn will be activated when floz(200cc) of oil remains in the reservoirThis will provide approximately 30 minutes of wide open throttle running before oil is depletedThe crankshaft driven oil pump injects oil into the fuel before the fuel pump
Oil Injection System
1Oil Reservoir The oil reservoir gravity fe eds oil to the oil pumpThe reservoir contains low oil sensor which activates warning horn when floz(200cc) of oil remains in the reservoir2Oil Injection Pump The crankshaft driven oil pump is variable ratio oil pump which provides an oilfuel mixture of 100:1 idle and 60:1 T3Check Valve Vent Provides air to oil reservoir for proper venting and also prevents oil le aks when outboard is tilted forward42 PSI Check Valve This valve prevents gasoline from being forced into oil line5Low Oil Sensor When oil level in reservoir drops to approximately floz(200cc), the sensor will signal warning module to activate warning horn6Timing and Protection Module (TPM) for (SN-0G589999Below) If the oil in the reservoir drops to less than floz(200 cc), the low oil sensor in the reservoir will signal the warning module to activate the warning hornIf the powerhe ad temperature should exce ed 190 (88 13 C), the overhe at temperature sensor in the water jacket cover will signal the warning module to activate the warning horn