Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 121Get this manual
Warning System Operation LOW OIL LEVEL
ENGINE OVERHEAT
The system is activated when the engine temperature is too hotThe system is activated when the oil in the engine mounted oil reservoir tank drops below 50 floz(1.5 liters) You still have an oil reserve remaining for 50 minutes of full speed operationNOTE: The engine mounted oil reservoir tank (located beneath the top cowl) along with the remote oil tank will have to be refilled
The TEMP light (a) will come on and the warning horn begins soundingThe warning system will automatically limit the engine speed to 3000 RPMIGNITION COIL, SENSOR, INJECTOR OR WARNING HORN NOT FUNCTIONING
The OIL light (a) will come on and the warning horn sounds series of four short tonesIf you continue to operate the outboard, the light will stay on and the horn will sound four short tones every two minutesThe engine has to be shut off to reset the warning systemOIL PUMP NOT FUNCTIONING ELECTRICALLY