I had a hammer & chisel Onan 2,500 watt 1,800 RPM generator that was propane. I loved that unit. Carried it in the back of a pickup. Started easy, ran well, and I used it for 5 minute to half hour jobs. It had stator winding starting so I started and stopped it to save fuel. What a sweetheart it was. During the sub zero winter I ran it on SAE 10W straight weight oil. Ever see 80hz powering a pair of Associated wheeled battery chargers? The Onan laughed it off. The days of getting away with murder. Linking a marine 8 volt battery with a similar amp hour six volt battery in series. When I connected those 2/0 jumper cables to a vehicle IT STARTED! Sub zero F, and the jumpered vehicle would SHIVER as the starter motor spun that engine. Can't do that now.