Mercury Mariner 4 and 5HP 4-Stroke Outboards Service Shop Manual 1999, Page 15Get this manual
MAINTENANCE
Flushing The Cooling System
Flush the internal water passages of the outboard with fresh water after each use in salt, polluted, or muddy waterThis will help prevent buildup of deposits from clogging the internal water passagesNOTE: Do not run the engine while flushing the cooling system
1Remove plug and gasket (aj and thread-in hose coupling (bj2Attach water hose to the hose couplingTurn on the water gently and flush the cooling system for to minutes3Remove the thread-in hose coupling and reinstall plug and gasketb
Fuel System
Avoid serious injury or death from gasoline fire or explosionCarefully follow all fuel system service instructionsAlways stop the engine and DO NOT smoke or allow flames or in the area while of the fuel Before servicing any part of the fuel systemstop engine and disconnect the batteryDrain the fuel system completelyUse an approved container to collect and store fuelWipe up any spillage immediatelyMaterial used to contain spillage must be disposed of in an approved receptacle Any fuel system service must be performed in well ventilated areaInspect any completed service work for sign of fuel leakage