398-06830-0 Tohatsu LANYARD STOP SWITCH

Fuel System Inspection
A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.
Illustration 1 g00550906
(1) Electronic Control Module (ECM). (2) Fuel filter. (3) The fuel gallery that is located within the fluid manifold. (4) Fuel tank. (5) Fuel transfer pump. (6) Fuel pressure regulating valve.
Check the fuel level in the fuel tank. Inspect the cap for the fuel tank. Make sure that the vent is not filled with dirt.
Clean the screen that is inside the inlet fitting of the fuel transfer pump.
Install a new fuel filter. Clean the primary fuel filter.
Remove any air that may be in the fuel system.If there is air in the fuel system, use the priming pump to open the drain valve on the fuel injection pump housing. Drain the fuel system until fuel without air flows from the drain line.Checking Engine Cylinders Separately
Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This can possibly be an indication of an injector with a defect. An extra high temperature at an exhaust manifold port can be an indication of too much fuel to the cylinder. High temperatures may also be caused by an injector with a defect.Refer to Testing And Adjusting, "Measurement of Exhaust Temperature" for the procedure for checking the temperatures in the exhaust manifold port.Start Up Procedure
Note: Refer to Operation and Maintenance Manual, "Engine Starting" in the Operation Section.If the fuel system has been worked on, use this starting procedure to start the engine:
Disconnect the air inlet system from the turbocharger.
Be careful when placing the steel plate against the opening on the turbocharger air inlet. To avoid crushed fingers, do not position fingers between the steel plate and the opening on the turbocharger air inlet. Due to excessive suction, the plate can be forcefully pulled against the opening on the turbocharger air inlet.
Another person will need to help as a precautionary step. This person should be ready to use the steel plate to cover the turbocharger air inlet if a problem occurs.Note: Make sure that the steel plate is large enough to cover the entire turbocharger air inlet.
Start the engine.Immediately place the steel plate against the opening on the turbocharger air inlet if the engine operates in one of the following ways:
The engine runs too fast.
The engine runs out of control.Covering the opening will stop the air supply to the engine. This will cause the engine to stop.Fuel Pressure
Table 1
Tools Needed    
Part Number     Part Name     Quantity    
1U-5470     Engine Pressure Group     1    
3Y-2888     Connector     1    
3J-1907     O-Ring Seal     1    Note: Both the 5P-2720 Probe Adapter and the 5P-2718 Pressure Probe can be used with these tools. Use these additional tools to allow the future installation of pressure probes.The 1U-5470 Engine Pressure Group can be used in order to check the engine's fuel pressures.
Illustration 2 g00284796
1U-5470 Engine Pressure Group (1) Pressure indicators. (2) Zero adjustment screw. (3) Pressure indicator. (4) Pressure tap. (5) Pressure indicator.This tool group has a gauge that is used to register the pressure in the fuel manifolds. The Special Instruction, SEHS8907 is with the tool group.During normal operating conditions and during load conditions, the fuel pressure should register within the following range:
310 to 415 kPa (45 to 60 psi)Fuel pressure to the fluid manifold should be as above, minus the delta P across the secondary fuel filter.The pressure drop across the secondary fuel filter is typically at least 35 kPa (5 psi) with a new filter. The pressure differential will increase as the filter accumulates deposits. If fuel pressure in the fuel gallery within the fluid manifold at the injectors decreases to approximately 69 kPa (10 psi), misfiring may occur.A check valve is mounted at the junction of the fuel lines. These fuel lines are located at the rear end of the fuel gallery that is located within the fluid manifold. The valve maintains fuel pressure at low engine speeds. The spring loaded check valve prevents the fuel from draining from the head after engine shutdown.To check the unfiltered fuel pressure, remove the plug from the fuel filter base. Install the connector, the seal and 1U-5470 Engine Pressure Group onto the fuel pressure tap. This will check transfer pump pressure. Operate the engine. To check the pressure within the main gallery, remove the plug from the fuel relief valve. Install the adapter, the seal and 1U-5470 Engine Pressure Group onto the fuel pressure tap. Operate the engine.Note: Make sure that the fuel filter is clean before you check fuel pressure. A restricted fuel filter will cause a lower fuel pressure at the fuel filter tap than the fuel pressure at the fuel relief valve.Finding The Top Center Position For The No. 1 Piston
Table 2
Tools Needed     Quantity    
9S-9082 Engine Turning Tool     1    Note: The starting position for all timing procedures is with the No. 1 piston at the top center position on the compression stroke.
Illustration 3 g00361852
Locating the top center position (typical example) (1) The storage location for the timing bolt. (2) Plug. (3) Bolt. (4) Cover.