Mercury Mariner 25HP 4-Stroke Outboard Service Manual 1997, Page 23Get this manual
Changing Engine Oil Engine Oil Capacity U.SQuarts (3.0 Liters)
Changing Oil Filter
1Place rag or towel below the oil filter to absorb any spilled oil2Unscrew old filter by turning the filter to the left3Clean the mounting baseApply film of clean oil to filter gasketDo not use greaseScrew new filter on until gasket contacts base, then tighten 34 to turn
Oil Changing Procedure
Pump Method 1Place the outboard in an vertical upright position2Remove dipstick and thread Quicksilver Crankcase Oil Pump (al onlo Ihe dipslick lubePump out the eng ine oil into an appropriate container