1986+ Mercury 6/8/9.9/10/15HP 2-stroke Factory Service Manual, Page 139Get this manual
FUEL DELIVERY SYSTEM
Fuel Pump
Removal and Disassembly
IMPORTANT: Fuel pump check valve diaphragm and gasket should NOT be re-used once the fuel pump is disassembled1Remove screws securing fuel pump assembly to carburetor2Separate fuel pump components
Cleaning and Inspection
1Clean and dry all parts thoroughly2Inspect pump body and base on carburetor for nicks, cracks or rough gasket surface3Inspect pump check valve diaphragmDiaphragm MUST BE flat and free from holes and imperfections4Pump body surface below check valves MUST BE flat so that check valve will seat