I think so, yes.
From what little I remember from a high school small engines
class, it would probably need to have the fuel mixture, and maybe the timing, adjusted.
Other threads have mentioned devices to clean up the biogas; those would probably be good for the engine, and the exhaust.
"the qualities of these bacteria, like the heat of the sun, electricity, or the qualities of metals, are part of the storehouse of knowledge of all men. They are manifestations of the laws of nature, free to all men and reserved exclusively to none." SCOTUS, Funk Bros. Seed Co. v. Kale Inoculant Co.