Running a propane powered engine compared to a gasoline powered engine is worlds apart in that don't get the smelly fumes, the engine needs less maintenance and the fuel doesn't go stale like gas. You do however get all the power you need with 104 octane fuel.
One of the first things I noticed when I saw this video besides the fact that it's the same model tiller as our converted tiller, is the chickens.
Propane engine conversions & poultry; homesteading at its best!