43 CFR 8343.1 - Standards.
(b) No off-road vehicle equipped with a muffler cutout, bypass, or similar device, or producing excessive noise exceeding Environmental Protection Agency standards, when established, may be operated on public lands.
(c) By posting appropriate signs or by marking a map which shall be available for public inspection at local Bureau offices, the authorized officer may indicate those public lands upon which no off-road vehicle may be operated unless equipped with a properly installed spark arrester. The spark arrester must meet either the U.S. Department of Agriculture - Forest Service Standard 5100-1a, or the 80-percent efficiency level standard when determined by the appropriate Society of Automotive Engineers (SAE) Recommended Practices J335 or J350. These standards include, among others, the requirements that: (1) The spark arrester shall have an efficiency to retain or destroy at least 80 percent of carbon particles for all flow rates, and (2) the spark arrester has been warranted by its manufacturer as meeting this efficiency requirement for at least 1,000 hours subject to normal use, with maintenance and mounting in accordance with the manufacturer's recommendation. A spark arrester is not required when an off-road vehicle is being operated in an area which has 3 or more inches of snow on the ground.
(d) Vehicles operating during night hours, from a half-hour after sunset to a half-hour before sunrise, shall comply with the following:
(1) Headlights shall be of sufficient power to illuminate an object at 300 feet at night under normal, clear atmospheric conditions. Two- or three-wheeled vehicles or single-tracked vehicles will have a minimum of one headlight. Vehicles having four or more wheels or more than a single track will have a minimum of two headlights, except double tracked snowmachines with a maximum capacity of two people may have only one headlight.
(2) Red taillights, capable of being seen at a distance of 500 feet from the rear at night under normal, clear atmospheric conditions, are required on vehicles in the same numbers as headlights.