Diesel Engine Bleed

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How to check if there is a fuel air lock in the diesel system.

This can happen if the Generator runs out of diesel while it is running, or after a repair, when air could have entered the system.

  • Start by removing the Rubber Fuel Line from before the injector pump on the front of the engine.
  • Turn on the fuel Petcock and make sure the fuel is free-flowing. If the fuel is not free-flowing, check the fuel is definitely turned on, also check if any filters are clogged and need to be replaced. Reattach this line to the Pump. 
  • Next, undo the metal fuel line from after the Pump and turn over the Engine until diesel flows from the Pump.
  • Now reattach the Metal Fuel Line to the Pump, clean up any spilled diesel (spilled fuel is a fire hazard!) and manually turn over the Engine.
  • Now, undo the Metal Fuel Line from the Injector end and turn over the Engine. Once the fuel is free-flowing from the Metal Fuel Line, reattach the Metal Fuel Line to the Injector.
  • This should ensure there is no longer an airlock in the system.


If you still cannot start the Engine:

  • Detach the Injector pipe from the Injector, remove the Injector from the cylinder head and now reattach the Injector to the Injector pipe. Point the Injector upwards and hold a clear glass over it. Turn over the Engine and hopefully watch the fuel spray into the glass. The Injector should release diesel from the 4 tiny holes with a strong jet. If the Injector does not spray from all 4 holes you will need to replace the Injector Nozzle.
  • If the spray into the glass is weak, then you will need to replace the Injector Pump.


If you had removed the Injector Pump previously, and the above does not fix the problem, it may be the Injector Pump Timing Shim(s) are missing or the Yoke (from the governor linkage inside the Engine) is not engaging with the Injector Pump. You can check the Yoke by removing the inspection plate on the front of the Pump and moving the Run/Stop lever. It should move the Yoke left and right, and in between the Yoke you should see the “Pump Pin” move too. If not, you will need to reinstall the Pump so this Pin is sitting between the Yoke. Please let us know if you need help with this.


Super-Silent Generators

Removing the canopy on these is very tricky and a lot of work, see if you can complete the repair before having to removing the canopy. You will only need to take the casing off if you need to replace the injector pipe or the nozzle.

Spanner Driver QUESTION

Did this fix the problem?

Spanner Driver Answer

Yes, thanks. Help me find my replacement parts.

Spanner Driver Answer

No, I need more help please.

Spanner Driver Answer

I fixed it!