Honestly, most of my experience with gasoline engines is before they became fuel injected. Diesels always have fuel delivered through at least one high pressure pump and "injectors" that atomize the fuel into the cylinder right before it explodes due to compression. Gas engines used to use a carburetor to mix gasoline and air together where it would be drawn into the cylinder just before a spark plug causes it to explode due to ignition. Using any kind of high pressure diesel pump requires that the entire length of suction and pressure pipe be leak free and 100% filled with fluid and absolutely no air. A tiny bubble of air will cause the high pressure pump not to pump and the diesel not to start, where it doesn't affect the gas engine. Depends on the engine, and I haven't looked at the Roxor, but some have a manual pump somewhere that you can use to "bleed" the air out of the system. Sometimes you can use the starter to bleed, but you would have to make sure the fuel filter was completely full and then go to each fuel line fitting from the injection pump out and crack the fitting to let out the air (and fuel). Probably four fittings on the pump and one fitting on each of 4 injectors. Often you will need to repeat this procedure more than once to get all the air out of the system. This is A LOT OF WORK. After you have to do this once I'm sure you will figure some way of always fueling your diesel before it runs out. And in case you didn't know, diesel fuel stinks, especially to wives. One drop will stay with you all day.