TESTING

1. Disconnect the negative battery cable.
2. Disconnect the fuel line from the carburetor.
3. Connect a fuel pressure gauge to the fuel line.
4. Disconnect the fuel return hose from the fuel pump and plug the fuel pump return outlet.

   Fig. 1: Testing the mechanical fuel pump using a fuel pressure gauge

5. Connect the negative battery cable and start the engine.
6. Check the fuel pressure while the engine is idling. The fuel pressure should be 3.7–4.7 psi.
7. Replace the pump if the pressure is not as specified.
8. Shut off the engine and disconnect the negative battery cable. Remove the fuel pressure gauge and reconnect the fuel lines.
9. Connect the negative battery cable.