Hey Koen, sorry to hear about your hand, and im also sorry that I looked at the pictures
I suspect that you may be right about the generator not being “quite right” as I also find it strange that I can drag the voltage way down without seeming to bog down the engine. It also tends to produce like 130+ volts when its idling, so maybe that would be worth checking out.
Unfortunately I never did run any tests with it on gasoline, and after a backfire during my early tests with woodgas, the carb has not seemed to be working right. I am not really sure where I would start in trying to track down that problem, as I am really not all that knowledgeable about gas engines. In fact, at this point I probably know more about running on charcoal, and my expertise there is clearly quite limited
There is a set-screw on the carb to adjust the idle, which I have not fussed with, but I did make a point to observe the governor on my last test, and it was moving to WOT when I applied the load. I can not say for certain if that was also the case when running a smaller nozzle hole. It was however a lot harder to get it to maintain 3500 RPM with the larger nozzle.
The charcoal seems to be fine, i finally have a supply of dry graded fuel, and if anything it was faster to flare with the larger hole. Flame has always been blue. The first puff of gas to come out of the blower sometimes appears hazy, but it quickly becomes invisible. The slag from all of my runs, regardless of nozzle size seems to form a glassy cone. I have yet to find any ash, or crumbly white powder that is not fused together.
What it seems like you are saying is that while this engine should maybe be capable of putting out more power, it is hard to gauge how much any percieved lack of power is due to the gas and how much is due to the condition of the engine? Are these small gas engines already a little low on compression for charcoal gas? I also cannot say for sure that this particular one has not been abused. I feel like I remember that someone mentioned that OHV engines were able to produce a bit more power than a regular flathead - anyone have thoughts on that?
I am fairly confident that the system is not leaking, and producing good gas, so I think I might try and build up the hole and re-drill it. I will maybe test something halfway between my starting point and where I am, and see how the output and vacuum respond.