1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 99Get this manual
Fuel Pump Operation 1The fuel pump is diaphragm pump which is mechanically driven off of the rocker arm2The black mounting block (insulator) and the two outlets on the fuel pump help prevent vapor lock3If the engine runs out of fuel, or has restriction preventing adequate fuel flow, the pump will make "clicking" noise
Fuel Pump Disassembly
1Remove screws to separate pump cover, cover seal, and diaphragm, from pump body
Fuel Pump Removal
1Remove sta-straps from fuel linesIMPORTANT: The hose fittings on the fuel pump can break if you try twisting or pulling the hoses offRemove hoses by slowly prying off the hoses using small screwdriver