539.21  MUFFLERS.
   No person shall operate a motor vehicle or motorcycle upon any roadway or drive located in any park grounds or other public lands unless the vehicle is equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise.  No person shall use a muffler cutout, bypass or other similar device upon any motor vehicle while it is being operated on such roadways and drives.  Every motorcycle muffler shall be equipped with baffle plates.