1983 Yamaha 30EN Outboards Service Manual, Page 36Get this manual
Remove the two bolts and remove the fuel pump Cleaning, inspection, and repair Fuel system trouble, in most cases, stems from fuel leakage, clogged strainer, or jammed or worn check valveTo check the fuel system, proceed as follows: 1Fuel joint and fuel hoses After cleaning the fuel joint, push the valve pin and blow the fuel joint with compressed air from the fuel hose sideIf fuel hoses are cracked or aged, they should be replaced
2Fuel pump
Remove the three screws, and remove the pump covers on the sides of both diaphragm and pump chamberWARNING: The fuel in the fuel pump should be drained into vessel or dry ragsNOTE: When removing the pump covers, use care not to break the diaphragm or gasketaChecking diaphragms Check the diaphragms for breakage, stretches, or deformation, and replace them, as requiredbChecking check valves Check the check valves for cracks or chips, and replace them, as requiredFuel filter Clean the filter of dust and impurities with suitable cleaning solvent, and blow it out with compressed air