Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 95Get this manual
3Remove screws and plate from pump cover to inspect check valvec b
Fuel Pump Reassembly
1Align the recess in the check valve and plate with the projection on the pump cover
aPump CoverPlateScrews
4Inspect check valve, gasket, and diaphragm replace if damagedaCheck ValvePlate
2Secure plate to pump cover with screwsc b