Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 113Get this manual
Fuel Pump RemovalDisassembly IMPORTANT: Fuel pump diaphragm and gaskets should not be re used once fuel pump is disassembled1
CleaningInspection
1Clean fuel pump housing, check valves, pulse chamber and pump base in solvent and dry all but check valves with compressed air
Disconnect fuel hoses from fuel pump
2Inspect each check valve for splits or chips3Inspect boost springs for weakness or breakage
2Disconnect pulse hose3Remove two mounting screws 4Remove fuel pump from engine
4Inspect fuel pump housing, pulse chamber and base for cracks or rough gasket surface and replace if any