Compiled Laws, Chapter 750. Michigan Penal Code § 750.242

Sec. 242.SPARK ARRESTERS ON TRACTION ENGINES USING WOOD FUEL--Any person who shall own or operate upon the premises of any inhabitant of this state, or upon the highway, any traction or other portable steam engine, unless said engine shall be equipped with an efficient spark arrester at all times when in use and using wood as a fuel, and with proper fire extinguishers, either liquid or dry, shall be guilty of a misdemeanor. All traction or other portable engines using wood for fuel shall be equipped with bonnet spark arresters having an oval top of number 10 mesh, 22 gauge wire and sides composed of number 6 mesh, 16 gauge wire.