Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 122Get this manual
WATER SEPARATING FUEL FILTER IS FULL OF WATER
ENGINE OVER-SPEED PROTECTION SYSTEM
The water level detection warning is activated when water in the water separating fuel filter reaches the full levelThe water can be removed from the filterThe WATER DETECTION light (a) will come on and the warning horn will begin sounding series of four beepsIf you continue to operate the outboard, the light will stay on and the horn will sound every two minutes
The system is activated when the engine speed exceeds the maximum allowable RPMAnytime the engine over-speed system is activated, the warning horn (a) begins to sound continuouslyThe system will automatically reduce the engine speed to within the allowable limitNOTE: Engine speed should never reach the maximum limit to activate the system unless the propeller is ventilating, an incorrect propeller is being used, or the propeller is faulty