2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 174Get this manual
OILING SYSTEM
COMPONENTS
OMS (Oil Metering System) Pump
40150 PL MODELS
The OMS pump is pulse driven, diaphragm-style pumpIt draws oil from the oil tank through the oil supply hose and supplies oil to the fuel chamber of the OMS pumpThe OMS pump "pre-mixes" the outboard lubricant (oil) with the fuel and supplies the fueloil mixture to the carburetors
Oil Output (Pressure) Switch
The oil pressure switch is integrated into the OMS pump and reacts to changes in oil pump pressureThe electronic module of the OMS pump monitors the internal oil flow of the pumpOMS pump
OMS Pump Diagram 1Oil pressure switch 2Electronic module 3Oil inlet
One pulse hose connects the pump to the pulse limiter on the front of the cylindercrankcase