0344038 EVINRUDE SCREW, Intake, inner

Illustration 1 g00690661
Fuel System Schematic
(A) Fuel priming pump (if equipped)
(1) Screen (if equipped)
(2) Inlet check valve
(3) Fuel transfer pump that is integral with the governor
(4) Outlet check valve
(5) Fuel filter
(6) Cylinder head
(7) Pressure regulating valve
(8) Check valve
(9) Primary fuel filter (if equipped)
(10) Pressure relief valve
(11) Fuel tank Fuel from fuel tank (11) is pulled through an in-line screen (1) by fuel transfer pump (3). The fuel transfer pump is integral with the governor. Fuel is sent from the fuel transfer pump through the pressure relief valve (10). The pressure relief valve is closed in normal operation. Fuel will enter through fuel filter (9) to a drilled passage in the cylinder head (6). Once the pressure of the fuel is greater than the desired range then the pressure relief valve will open. This will allow the fuel to return to the tank. The drilled passage in the cylinder head intersects a gallery around each unit injector in order to provide a continuous flow of fuel to all injectors.When there is air on the inlet side of the fuel system, fuel priming pump (A) (if equipped) may be used in order to fill the fuel filter and the fuel gallery that is in the cylinder head. This is performed before the engine is started. When the priming pump is used, check valves that are located in the fuel priming pump control the movement of the fuel. The fuel is forced through the low pressure side of the fuel system. This removes air from the fuel lines and components back into the fuel tank.
Illustration 2 g00690672
Lines Group For The Fuel Filter
(3) Fuel transfer pump that is integral with the governor
(5) Fuel filter
(6) Cylinder head
(10) Pressure relief valve
(12) Fuel outlet port to the fuel tank
(13) Fuel inlet port to the fuel transfer pump
(14) Fuel filter base
(15) Pressure tap for filtered fuel
(16) Tube assembly from the fuel filter base to the fuel gallery in the cylinder head
(17) Tube assembly from the transfer pump to the fuel filter base
Illustration 3 g00690675
Lines Group For The Fuel Filter
(1) Screen
(6) Cylinder head
(7) Pressure regulating orifice
(8) Check valve
(10) Pressure relief valve
(12) Fuel outlet port to the fuel tank
(13) Fuel inlet port to the fuel transfer pump
(17) Tube assembly from the transfer pump to the fuel filter base
(18) Tube assembly from the fuel passage in the cylinder head to the fuel tank Fuel Transfer Pump
Illustration 4 g00690711
Fuel Transfer Pump
(A) Inlet flow of fuel
(B) Outlet flow of fuel
(1) Screen (if equipped)
(2) Inlet check valve
(3) Spring
(4) Piston assembly
(5) Outlet check valve
(6) Piston check valve
(7) Tappet assembly
(8) Camshaft
(9) Passage The fuel transfer pump is located in the front housing of the governor. The pump is activated by camshaft (8) that is attached to the shaft of the governor drive gear. Piston assembly (4) and tappet assembly (7) are stroked up and down by the camshaft and spring (3).Fuel enters the transfer pump through screen (1) (if equipped) and inlet check valve (2). On the upstroke of piston assembly (4), check valve (2) closes. Outlet check valve (5) closes in order to prevent fuel from being pulled back in the pump from the outlet. As pressure increases above piston assembly (4), piston check valve (6) opens in order to fill the cavity above the piston assembly.On the downstroke, as the fuel pressure in passage (9) increases, piston check valve (6) is closed and outlet check valve (5) is opened. This causes fuel to be pushed through the secondary fuel filter and to the engine. Inlet check valve (2) opens in order to allow fuel to fill the cavity above piston assembly (4).During engine shutdown, the check valves are held closed by springs.Fuel Injection Pump (Unit Injector)
Illustration 5 g00691325
Fuel Injection System
(1) Rocker arm
(2) Setscrew
(3) Floating button
(4) Tappet Spring
(5) Pushrod
(6) Plunger
(7) Rack
(8) O-ring
(9) Barrel
(10) Fuel gallery
(11) Sleeve
(12) O-ring
(13) Lifter
(14) Camshaft The fuel injection pump (unit injector) allows a small amount of fuel to be injected at the proper time into the combustion chamber. The fuel that is supplied to fuel gallery (10) surrounds each unit injector. Each of these galleries are connected by a drilled passage in the cylinder head. This passage provides a continuous flow of fuel to all unit injectors.The unit injector is isolated from the coolant passages by sleeve (11). The sleeve also provides the seating surface for the unit injector.Injection timing is determined by the angular location of camshaft (14) and the vertical location of plunger (6) in barrel (9). The camshaft gear and the crankshaft gear mesh together at the front of the engine in order to achieve the angular location of the camshaft. The location of the plunger (fuel timing) is adjusted by setscrew (2).The profile of the camshaft is sent to rocker arm (1) by lifter (13) and pushrod (5), as the camshaft rotates. The motion of rocker arm (1) is then sent to plunger (6) through the floating button (3).
Illustration 6 g00691353
Fuel Injection Pump (Unit Injector)
(4) Tappet spring
(6) Plunger
(7) Rack
(8) O-ring
(9) Barrel
(12) O-ring
(15) Gear
(16) Sleeve filter
(17) Helix
(18) Lower port
(19) Upper port
(20) Spring
(21) Check (needle valve) At the top of the plunger's stroke, fuel from fuel gallery (10) enters the unit injector around the edges of sleeve filter (16). The fuel then fills the volume below plunger (6).During the plunger's downward motion, fuel beneath the plunger is displaced into the gallery through the two ports in barrel (9). As upper port (19) is closed by the bottom edge of the plunger, fuel continues to be displaced through lower port (18). When the lower port is closed, effective stroke begins. The fuel inside the unit injector becomes pressurized by the continued downward movement of the plunger. When the fuel pressure is sufficient to open check (21), high pressure fuel will be forced through orifices at the bottom of the nozzle into the combustion chamber. This will continue until upper port (19) is uncovered by helix (17) on the plunger. At this instant, effective stroke ends and this high pressure fuel will spill through upper port (19) into the gallery. This will allow spring (20) to