FUEL SYSTEM FUEL PUMP 5 A Index Table of Contents Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . Replacement Parts Warning . . . . . . . . . . . . . . Torque Specifications . . . . . . . . . . . . . . . . . . . . Tools/Lubricants/Sealants . . . . . . . . . . . . . . . . Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel Delivery System . . . . . . . . . . . . . . . . . . . . Recommendations . . . . . . . . . . . . . . . . . . . . Description . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5A - 1 5A - 1 5A - 1 5A - 1 5A - 1 5A - 2 5A - 2 5A - 2 5A - 2 Fuel System Components (Typical) . . . . . . . . Water Separating Fuel Filter . . . . . . . . . . . . . . Replacement . . . . . . . . . . . . . . . . . . . . . . . . . Fuel Pump Fuel Filter . . . . . . . . . . . . . . . . . . . . Replacement . . . . . . . . . . . . . . . . . . . . . . . . . Testing Fuel Pump . . . . . . . . . . . . . . . . . . . . . . Fuel Pump Replacement . . . . . . . . . . . . . . . . . Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5A - 3 5A - 3 5A - 3 5A - 4 5A - 4 5A - 4 5A - 5 5A - 5 NOTICE For information and procedures on troubleshooting, refer to SECTION 1C. Index 5A- -0FUEL DELIVERY 5A - FUEL PUMP SYSTEM 90-816462 2-695 2-695 90-816462 Identification Torque Specifications Description Fuel Inlet and Outlet Fittings Lb. Ft. N⋅m Tighten finger tight then 1-3/4 to 2-1/4 turns with wrench. (See Note) Fuel Line to Fuel Outlet Fitting Fuel Pump to Block Securely 20 27 NOTE: Apply #592 Loctite Pipe Sealant with Teflon. Do not use Teflon Tape. Tools/Lubricants/Sealants Carter Fuel Pump Description Replacement Parts Warning ! WARNING Electrical, ignition and fuel system components on your MerCruiser are designed and manufactured to comply with U.S. Coast Guard Rules and Regulations to minimize risks of fire and explosion. Use of replacement electrical, ignition or fuel system components, which do not comply with these rules and regulations, could result in a fire or explosion hazard and should be avoided. Part Number Fuel Pressure Gauge 91-16850A1 Quicksilver Perfect Seal 92-34227-1 Quicksilver Needle Bearing Grease 92-42649A1 Obtain Locally Loctite Pipe Sealant with TEFLON Specifications Type of Fuel Pump Carter Pump Pressure (1800 RPM) 5-1/4 - 6-1/4 PSI (36-44 kPa) ! WARNING Avoid gasoline fire or explosion. Improper installation of brass fittings or plugs into fuel filter base can crack casting and/or cause a fuel leak. • Apply #592 Loctite Pipe Sealant with Teflon to threads of brass fitting or plug. DO NOT USE TEFLON TAPE. • Thread brass fitting or plug into fuel filter base until finger tight. • Tighten fitting or plug an additional 1-3/4 to 2-1/4 turns using a wrench. DO NOT OVER-TIGHTEN. • Install fuel line. To prevent over-tightening, hold brass fitting with suitable wrench and tighten fuel line connectors securely. • Check for fuel leaks. Index 90-816462 2-695 FUEL PUMP - 5A - 1 Precautions ! WARNING Always disconnect battery cables from battery BEFORE working on fuel system to prevent fire or explosion. ! WARNING Be careful when changing fuel system components; gasoline is extremely flammable and highly explosive under certain conditions. Be sure that ignition key is OFF. DO NOT smoke or allow sources of spark or flame in the area while changing fuel filters. Wipe up any spilled fuel immediately. ! WARNING Make sure that no fuel leaks exist before closing engine hatch. ! CAUTION DO NOT operate engine without cooling water being supplied to seawater pickup pump, or pump impeller will be damaged and subsequent overheating damage may result. ! WARNING Avoid gasoline fire or explosion. Improper installation of brass fittings or plugs into fuel filter base can crack casting and/or cause a fuel leak. • Apply #592 Loctite Pipe Sealant with Teflon to threads of brass fitting or plug. DO NOT USE TEFLON TAPE. • Thread brass fitting or plug into fuel filter base until finger tight. • Tighten fitting or plug an additional 1-3/4 to 2-1/4 turns using a wrench. DO NOT OVER-TIGHTEN. • Install fuel line. To prevent over-tightening, hold brass fitting with suitable wrench and tighten fuel line connectors securely. • Check for fuel leaks. Fuel Delivery System Recommendations ! WARNING Boating industry standards (BIA, ABYC, etc.) federal standards and Coast Guard regulations MUST BE adhered to when installing fuel delivery system. When designing and installing fuel delivery system, the following information MUST BE observed: 1. Fuel tank should be mounted below carburetor level, if possible. If tank is mounted above carburetor level, gravity feed may cause carburetor fuel inlet needle to unseat, and flooding may result. 2. Fuel pickup should be at least 1 in. (25 mm) from the bottom of the fuel tank to prevent picking up water or other impurities. 3. Fuel lines used MUST BE Coast Guard approved (USCG type A) and MUST NOT BE SMALLER THAN 3/8 in. (9.5 mm) I.D. On installations where long lines or numerous fittings are required, larger size lines should be used. 4. Fuel line should be installed free of stress and firmly secured to prevent vibration and/or chafing. 5. Sharp bends in fuel line should be avoided. 6. A flexible fuel line must be used to connect fuel line to engine to absorb deflection when engine is running. Description The fuel system consists of fuel tank(s), a water separating fuel filter, an electric fuel pump and a carburetor. The fuel is stored in the fuel tank. When the fuel pump is energized by turning on ignition switch, fuel is drawn from the fuel tank, through the water separating filter, by the electric fuel pump. The fuel is pushed through the fuel line to the carburetor where it is metered and supplied to the engine. Index 5A - 2 - FUEL PUMP 90-816462 2-695 Filter should be replaced when fuel flow is restricted or filter flow is questionable. DO NOT attempt to flush out filter. Fuel System Components FUEL SYSTEM Replacement i NOTICE Refer to “Precautions,” in this section, BEFORE proceeding. g b c f d h 1. Disconnect battery cables from battery. e a 50830 3. Lubricate sealing ring(s) of new filter with SAE engine oil. Typical a b c d e f g h i - 2. Remove fuel filter from base. A filter wrench may be needed to loosen element. Fuel Tank Anti Siphon Valve Water Separating Fuel Filter Fuel Pump Carburetor Fuel Filter Vent Hose Fuel Line Sight Tube 4. Install new filter, tightening securely by hand. 5. Reconnect battery cables. Make sure water is supplied to cooling system and start engine. Check for fuel leaks. Water Separating Fuel Filter (If So Equipped) The fuel filter consists of the fuel filter base and filter element. a a c b c 72678 a - Filter Base/Mounting Bracket b - Filter Element c - Sealing Ring b 72678 a - Filter Mounting Bracket b - Filter Element c - Sealing Ring Index 90-816462 2-695 FUEL PUMP - 5A - 3 9. Check for gasoline leaks. Fuel Pump Fuel Filter NOTICE Refer to “Precautions,” in this section, BEFORE proceeding. 10. If leaks exist, STOP ENGINE and recheck connections. Testing Fuel Pump Replacement INSPECTION Fuel pumps are equipped with a sight tube. Any evidence of fuel in the sight tube indicates a ruptured diaphragm and fuel pump must be replaced immediately. NOTICE Refer to “Precautions,” in this section, BEFORE proceeding. 1. Disconnect battery cables from battery. 2. Remove fuel line from carburetor or outlet side of fuel pump. 3. Install Fuel Pressure Connector (91-18078) to carburetor or fuel pump and reinstall fuel line. Tighten connector and fuel line securely. 4. Connect fuel pressure test gauge to connector. a a b 50738 a - Sight Tube b - Fuel Fitting NOTE: This fuel pump must be replaced as an assembly; it is not repairable with a diaphragm kit. c 1. Disconnect battery cables from battery. b ! CAUTION Plug fuel supply hose after removal to prevent fuel from leaking into boat. 2. Remove safety wire. 3. Loosen screw from filter bowl bail and release bail from fuel pump housing. 4. Remove bowl, filter element, spring, and gasket from fuel pump. 5. Install new filter. 6. Tighten retaining screw securely. 71561 a – Fits into Carburetor b - Fuel Line Connection c - Fuel Gauge Barb 5. Reconnect battery cables, start engine, and run at idle, making sure water is supplied to the cooling system. 6. Fuel pressure should be within specifications. If not, replace fuel pump. 7. Remove fuel pressure gauge and connector tool. Reconnect fuel line to fuel pump. 7. Install safety wire and tighten securely. 8. Start and run engine. Index 5A - 4 - FUEL PUMP 90-816462 2-695 • Fuel Pump Replacement Check for fuel leaks. 5. Install fuel outlet fitting (from old pump) into fuel pump. Removal 1. Remove fuel inlet and outlet lines at fuel pump. 6. Install fuel line to fuel outlet fitting. Tighten securely. 2. Remove sight tube. 7. Install fuel inlet fitting to fuel pump. 8. Install sight tube and fuel supply line. 9. Start engine and check for fuel leaks. a b 50738 a - Sight Tube b - Fuel Fitting 3. Remove 2 fuel pump mounting bolts and lockwashers, pump and gasket. ! CAUTION Plug fuel lines after disconnecting from fuel pump to eliminate any chance of fuel siphoning into bilge. 4. Install new gasket (coat both sides with Perfect Seal) on fuel pump. Install pump, and torque mounting bolts to specifications. ! WARNING Avoid gasoline fire or explosion. Improper installation of brass fittings or plugs into fuel filter base can crack casting and/or cause a fuel leak. • Apply #592 Loctite Pipe Sealant with Teflon to threads of brass fitting or plug. DO NOT USE TEFLON TAPE. • Thread brass fitting or plug into fuel filter base until finger tight. • Tighten fitting or plug an additional 1-3/4 to 2-1/4 turns using a wrench. DO NOT OVER-TIGHTEN. • Install fuel line. To prevent over-tightening, hold brass fitting with suitable wrench and tighten fuel line connectors securely. Index 90-816462 2-695 FUEL PUMP - 5A - 5