The most accurate method for troubleshooting the fuel pump on your Evinrude is to test the pump with a low-pressure fuel gauge while running the motor at various speeds with the propeller attached. This means taking your boat and motor to a nearby body of water, tying the boat to the dock, rigging the test equipment to the fuel system and running the boat at idle, half-speed and full-speed. If the pump is operating properly, you'll find yourself forced to go boating. If the pump is not working properly, change out the pump -- then go boating.
Inspect the fuel filters to ensure they are clean and serviceable. Start and run the engine in forward gear, at idle, until normal operating temperature is reached. Shut the motor down.
Remove the fuel tank cap and clear the fuel tank vent. If your outboard is supplied from a portable fuel tank, ensure it's not located more than 30 inches lower than the fuel pump mounting point.
Slip a drain pan under the fuel hose connections you will be disconnecting. Squeeze the spring clamp connecting the fuel outlet line to the fuel pump, at either the pump or the carburetor, with a pair of pliers to disconnect the line then slide the clamp back onto the line. Disconnect the fuel output hose from either the carburetor or fuel pump in the same way.
Connect a fuel pressure gauge inline between the pump and the carburetor by pushing the nipples at the ends of the lines into the gauge. Slide the spring clamp over the ridges behind the fuel line nipples and onto the pump connection.
Run the engine at 600 RPM and observe the pressure on the gauge, which should read about 1 PSI, or 7 kPa. Increase the engine's speed to between 2,500 and 3,000 RPM; the gauge should read about 1.5 PSI, or 10 kPa. Speed the motor up once more, at 4,500 RPM, and the gauge should show about 2.5 PSI, or 17 kPa.
Items you will need
- Low-pressure fuel pressure test gauge
- Clean up any fuel that spills and pour the fuel from the drain pan back into the tank.
- Remove any ignition source from the immediate vicinity of the test or the drain pan. Clean up any spills.
- "Evinrude Repair Manual -- 2.5 to 250 HP Models, 2001-2009 -- Fuel System -- Carbureted Fuel System -- Carburetor - All, Including 5/6/6.5/8 (164cc), 9.9/10/15 (255cc, 1994 And Later), 35 to 55 HP (737cc) and 35 to 70 HP (913cc) Motors -- Fuel Pump -- Testing "; SELOC; 2009