OK, so it's like this:
Motor -> 4.09kW mechanical power ->
electric generator -> 4.09kW electric power ->
gas generator -> 4.09kW of gas (> 1747 l/hr) ->
motor.

We know a petrol motor has <30% efficiency, so one of the other components must have >100% efficiency. If you find that component, you can trade it in for a Nobel prize.


The engine in the video can't run a 3kW generator with that rate of gas usage. You could see it was idling very slowly and I think it stalled once or twice. Don't forget that if you put a load on the shaft, then even at the same RPM, it consumes fuel faster.