If it starts, runs for a few minutes, then it is probably a fuel problem. The only other thing I can think of is the temp or oil pressure sensor is tripping out, and maybe it is bad.
David
What is the exact model?
Is there any instability that you can hear or feel or see in theboutlut, or just a sudden shutdown?
What type(s) of load(s) have been present when the problem was exhibited?
Normally instability before shutdown points to fuel. Hard shutdown pointa to a safety sensor (water temp, exhaust temp, oil pressure, output voltage, etc), which could be a sensor, something in the circuit, or a real performance problem, e.g. clogged intake or cooler or bad impeller or overload, etc
I know that diesel motor just stop if miss fuel, but the new ones, with a lot of sensors, stop if one of them have problem
I think must be one sensor, but how to test each one?
Have you checked the V-belt? If it fails, this is the exact symptom because the engine overheats pretty quickly with both water pumps not turning.
Mine was doing the same (on a Westerbeke). It was the water temp sensor, went bad. Easy fix... If it were me, I would buy all the sensors the gen has. Replace which one is bad. Then you have spares for the others and order another of the one that was bad...