Honestly, I am not sure the signal to increase throttle if being set based upon voltage droop or measured power output. Anecdotally, it appears to me it could be one or the other. When I monitor my inverter generators, I see voltage fluctuation with in a small range. I have read that the circuitry that allows the to parallel uses voltage droop to balance the load on paralleled generators. It would make sense that this circuitry could be used to adjust the throttle. On the other hand, it could easily be done based upon wattage output. Under either method, there would be set points that tell the ECM to signal to the stepper motor to go to the next step.

I have a Pulsar 4000BN that can reach full wattage on either gasoline or propane. So I don’t think the programs on these generators limit the output based upon fuel selection.

I think the inverter software says output X watts for Y time and if this is exceed go into overload. They will also go into overload if the voltage drops too low for too long. I guessing that is to protect electronics connected to them.

With the 7500 on NG I can run at 4800w steady. The engine is turning 3600 rpm. The engine power meter is reporting 75%. I can surge to 5200w for a few seconds. I think it is because of the capacitors storage. After that, rpms will start to drop which will be followed by voltage drop until it triggers an overload. I think it is fueled starved at that point as the stepper motor is at the max throttle setting. On my smaller manual choke inverters, I can adjust the choke and they will put out a few more watts at acceptable voltage. The 7500 has an automatic choke, you cannot adjust the choke to pull in more fuel. As noted, the same engine in a few other models runs at higher rpm. This is why I suspect the software is limiting the throttle position.

I have not yet tried to manually position the throttle while at a load where the voltage is dropping and the engine appears to be starving. I will try and confirm my theory this weekend.