I didn't know about that one, thanks.
Harry K
It used gas to start, then switched to diesel. Then run it on gas before quitting so the carb had gas in it for starting.
From:
https://smallfarmersjournal.com/john-deere-model-a-tractor/
Fuel System… Gravity-feed fuel system. Gasoline tank capacity—1 U.S. gallon. Fuel tank capacity—15 U.S. gallons.