There was only one diesel engine that was worth fitting to a bike - and a BMW or Guzzi, at that.
The 1L 3-pot Daihatsu turbo diesel produced a worthwhile amount of power and could mate to the BMW or Guzzi 'box relatively easily, AND still put in a decent turn of speed.
All these utter abortions with single cylinder ditch pump engines are a 'kin joke.