See Figure 1
Air entrapped in the fuel system can cause inadequate fuel injection, poor operation, and hard starting. Whenever the fuel system is serviced, it should be bled of entrapped air in the proper sequence.
- Loosen the fuel filter petcock or valve and operate the priming pump on the feed pump. If the filter is filled with fuel, fuel containing air bubbles will be discharged from the petcock or valve. Continue pumping until the discharge fuel contains no more air bubbles. Then tighten the fuel valve or petcock securely.
- Loosen the air bleeder screw at the top of the injection pump and operate the priming pump. Continue pumping until all air is bled from the fuel in the pump reservoir. Then close the air bleeder screw securely.