I bought one of those some years ago at Meijer for under $100 and started a thread on it. Changing the Torch spark plug didn't help. I got fed up with it and started a thread wanting to do an oil gas mix experiment using Wesson vegetable oil, but someone here acted like I should really give it to a person who needs a POS generator that might not start and stay running in an emergency for their oxygen machine or something.
I still suspect it makes more heat and noise than it does electricity.
I have a couple of older blue ones. Those are great! Mine ran our refrigerator and mom's oxygen concentrator at the same time. Used it @ night so that we did not have to hear my 4k industrial generator all night long. One of mine must have 400+ hrs on it by now.
I used one (similar to that) a couple of years ago. It was small enough that I could stash it in my daughter's tree-house and have it running DURING the hurricane. It powered 2 TVs and Sat. receivers and an internet modem along with a few lamps until daybreak when I could get the 'big' generator out to run fridge, freezer, etc.
45 years ago, I worked for Duke Power (now Duke Energy). We had, as I remember, the 2 most efficient steam turbine powered plants in the US. A quick Google search on our then leading Belews Creek plant yields: "During 2006, it was the fifth most efficient coal power plant in the United States with a heat rate of 9,023 Btu/kWh (37.8% conversion efficiency). The remaining 62.2% of energy released by the burning coal is in the form of heat.