REMOVAL & INSTALLATION
- Loosen the threaded fuel line connection(s) with a tubing wrench, then tighten snugly. Do not remove the lines yet.
- Loosen the fuel pump mounting bolts 1-2 turns. If the fuel pump does not come loose from its mounting, the gasket is probably stuck; apply force with your hands to loosen the pump.
- Rotate the crankshaft with the starter until the fuel pump eccentric is near its low position, reducing the tension on the fuel pump rocker arm. It will now be easier to remove and install the fuel pump.
- Disconnect the negative battery cable.
- Disconnect the fuel pump inlet, outlet and fuel vapor return line, if equipped.
- Remove the fuel pump mounting bolts and remove the fuel pump. Discard the old gasket.
- Clean all old gasket material from the pump mounting surface on the engine and from the fuel pump, if it is to be reused.
- Apply a coat of oil resistant sealer to a new gasket.
- Install the mounting bolts into the fuel pump and install the gasket on the bolts. Position the pump on the engine. Turn the mounting bolts alternately and evenly and tighten to 19-27 ft. lbs. (26-37 Nm).
- Connect the fuel pump outlet line. If it is a threaded connection, start the fitting by hand to avoid cross-threading. Tighten the fitting to 15-18 ft. lbs. (20-24 Nm).
- Connect the inlet line and fuel vapor return line, if equipped. Tighten the hose clamp(s).
Prior to installation, check the rubber fuel lines and make sure they are not cracked, hardened or frayed. If replacement is necessary, use only rubber hose made for fuel line use.
- Connect the negative battery cable, start the engine and check for leaks.
- Stop the engine and check all fuel line connections for leaks. Check the fuel pump mounting pad for oil leaks.
See Figure 1
- Remove the air cleaner assembly.
- Using a backup wrench on the carburetor inlet nut, slowly disconnect the fuel line from the carburetor.
- Attach a piece of rubber hose to the end of the fuel line and direct the other end of the hose into a suitable container.
Crank the engine 10 revolutions. If little or no fuel flows from the fuel line during the tenth revolution, check the following:
- Make sure there is fuel in the fuel tank and the fuel tank outlet is not plugged or restricted.
- If there is an in-line filter between the fuel pump and carburetor, make sure it is not plugged.
- Check all fuel lines for kinks, cracks and leaks.
- Check the fuel pump diaphragm crimp area and breather hole(s) for fuel or oil leaks.
- If there is an adequate fuel supply and there are no restrictions or leaks, replace the fuel pump.
- If the fuel flow is adequate, perform the pressure test.
- Connect a suitable pressure gauge to the carburetor end of the fuel line.
- Start the engine and read the pressure after 10 seconds. The engine should be able to run for over 30 seconds on the fuel in the carburetor bowl.
- The fuel pump pressure should be 6-8 psi. If pump pressure is too low or too high, install a new fuel pump.
- Connect the fuel line to the carburetor, using a backup wrench on the carburetor inlet fitting.
- Install the air cleaner assembly.