Hope this is the correct section for this as the typical topics here seemed the most appropriate.

I have a 5.5 KW KOOP (chinese ) diesel backup generator that ran fine for the past 5 years. It came installed when i bought the house so not sure who the agents are or if there even are any.

I serviced it annually by changing oil and draining the fuel tank and replacing filters. On a recent test run it would start (electric start), run for a few seconds and then die. Almost as if it was starved of diesel but after again draining/cleaning the fuel tank and replacing the filters it still does the same. It would run for a few seconds and die and will not start again. However after standing for about 10 minutes or so it will start again and repeat the same. I checked and it does not seem to be a fuelling issue as the diesel flows freely when removing the hose after the filter. I'm not familiar with these types of engines but assume there must be some kind of electrically controlled decompression valve for starting that could cause issues?

Does anyone know what the cause could be or where to start fault finding? Failing that, any reputable service/repair shops in the Vaal or Joburg area?