853740017 Mercury CABLE, Ground (Manual)

Engine Design
Cylinder And Valve LocationBore ... 137.2 mm (5.40 in)Stroke ... 152.4 mm (6.00 in)Arrangement of Cylinders ... 65 degreesNumber of Cylinders ... V-12Valves per Cylinder ... 4Combustion ... Direct InjectionFiring Order (Injection Sequence) ... 1,4,9,8,5,2,11,10,3,6,7,12Rotation of Crankshaft (when seen from flywheel end) ... counterclockwiseRotation of Fuel Pump Camshaft (when seen from pump drive end) ... counterclockwise Front end of engine is opposite to flywheel end. Left side and right side of engine are as seen from flywheel end. No. 1 cylinder is the front cylinder on the left side. No. 2 cylinder is the front cylinder on the right side.Fuel System
Fuel System Schematic-Typical Example
(1) Fuel line (to injection pump housing). (2) Injection pump housing. (3) Return line (to tank). (4) Direct injection adapter. (5) Fuel manifold. (6) Priming pump. (7) Bypass valve. (8) Fuel tank. (9) Secondary fuel filters. (10) Fuel line (from transfer pump to secondary fuel filters). (11) Fuel transfer relief valve. (12) Fuel transfer pump. (13) Fuel line (from primary fuel filter to fuel transfer pump). (14) Primary fuel filter. (15) Fuel line (from tank to primary fuel filter).This engine has a pressure type fuel system. There is one fuel injection pump and one fuel injection nozzle for each cylinder. The fuel injection pumps are located in injection pump housing (2). The fuel injection nozzles are installed in direct injection adapters (4) under the valve covers.When the engine is running, fuel is pulled from fuel tank (8) through fuel line (15) and primary fuel filter (14) by fuel transfer pump (12). The transfer pump pushes the fuel through secondary fuel filters (9), to manifold (5) of injection pump housing (2).The fuel manifold (5) supplies fuel for each fuel injection pump. Some of the fuel in the manifold is constantly sent through an orifice in the fitting that connects the manifold to return line (3). The orifice controls the pressure in the manifold and the amount of fuel that goes back to the fuel tank. The constant flow of fuel back to the tank removes air from the system.Individual fuel injection lines carry fuel from the fuel injection pumps to each cylinder. One section of line connects between the fuel injection pump and an adapter on the valve cover base. Another section of line on the inside of the valve cover base connects between the adapter and the fuel injection nozzle.The fuel transfer pump (12) is installed on a drive adapter that is fastened to the rear of the fuel injection pump housing. Fuel transfer pump (12) has a pressure relief valve (11) and a bypass valve (7). Pressure relief valve (11) is located in the transfer pump cover and controls the maximum pressure of the fuel to the fuel injection pump housing. When the pressure gets too high, relief valve (11) opens and directs fuel back to the inlet side of the transfer pump. Bypass valve (7) allows fuel to go around the transfer pump gears when fuel priming pump (6) is in use.When there is air on the inlet side of the system, fuel priming pump (6) is used, before the engine is started, to fill the low pressure side of the fuel system from the fuel tank. When the priming pump is used, movement of fuel through the low pressure side of the system removes air from the lines and components back into the fuel tank.There is no bleed orifice or valve installed on the fuel injection pump housing to vent air from the high pressure part of the fuel system. Air trapped in the fuel injection lines can be vented by loosening all of the fuel injection line nuts where they connect to the adapters in the valve cover base. Move the governor lever to the low idle position. Crank the engine with the starting motor until fuel without air comes from the fuel line connections. Tighten the fuel line nuts. This procedure is necessary because the fuel priming pump will not give enough pressure to push fuel through the reverse flow check valves located in the fuel injection pump bonnets.The injection pumps are in time with the engine and send fuel to the injection nozzles under high pressure. When the fuel pressure at the injection nozzle is high enough the nozzle opens and sends fuel into the combustion chamber.
Location Of Fuel System Components
(1) Fuel line (to injection pump housing). (2) Injection pump housing. (3) Return line (to tank). (5) Fuel manifold. (10) Fuel line (from transfer pump to secondary fuel filters). (11) Fuel transfer relief valve. (12) Fuel transfer pump. (13) Fuel line (from primary fuel filter to fuel transfer pump).An automatic timing advance unit is mounted on the front of the fuel injection pump camshaft. It is driven by the engine camshaft gear inside the front timing gear housing. The automatic timing advance unit gives easier starting and smooth low speed operation. It will also advance timing as engine speed increases to give correct engine operating efficiency.Fuel Injection Pump
Cross Section Of The Fuel Injection Pump Housing
(1) Fuel manifold. (2) Inlet passage. (3) Check valve. (4) Pressure relief passage. (5) Pump plunger. (6) Spring. (7) Gear. (8) Fuel rack (left). (9) Lifter. (10) Link. (11) Lever. (12) Camshaft.The rotation of the cams on the camshaft (12) cause lifters (9) and pump plungers (5) to move up and down. The stroke of each pump plunger is always the same. The force of springs (6) hold lifters (9) against the cams of the camshaft.The pump housing is a "V" shape (similar to the engine cylinder block), with six pumps on each side.When the pump plunger is down, fuel from fuel manifold (1) goes through inlet passage (2) and fills the chamber above pump plunger (5). As the plunger moves up it closes the inlet passage.The pressure of the fuel in the chamber above the plunger increases until it is high enough to cause check valve (3) to open. Fuel under high pressure flows