Mercury Mariner 30/40 4-Stroke Outboard Service Manual 1998, Page 17Get this manual
MAINTENANCE
After Each Use
1Flush out the outboard cooling system if operating in salt or polluted water2Wash off all salt deposits and flu sh out the exhaust outlet of the propeller and gear case with fresh water if operating in salt water
Every 100 Hours of Use or Once yearly, Whichever occurs first
1Lu bricate all lubrication pai ntsLubricate more frequently when used in salt water2Change engine oil and replace the oil filterThe oil should be changed more often when the engine is operated under adverse conditions such as extended trolling3Inspect thermostat visually for corrosionbroken spri ng, and to dete rmine that the valve is com pletely closed at room temperature If questionabl e, inspect thermostat as outlined in Section 4B "Thermostat"4Inspect and clean spark plugs5Check engine fu el filter for contaminants6Adjust carburetor(s) (if required) 7Check engine timing setup8Check corrosion control anodesCheck more freq uently when used in salt water9Drain and replace gear case lubricant10Lubricate splines on the drive shaft11Check and adjust valve clearanceif necessary12Check power trim fluid3Inspect battery14Check control cable adjustments 15Inspect timing belt16Remove engine deposits with Quicksilver Power Tune Engine Cleaner17Check tightness of bolts, nuts, and other fasteners