I read through the WI snowmobile regs book and the words LED were never mentioned. It states: copy/paste...
Equipment—Lights, Reflectors and Exhaust Requirements.
Your snowmobile must have a white headlamp and a tail lamp that is turned on during the hours of darkness or when you are riding on a highway right-of-way. It is recommended that your lights stay on whenever you ride.
Designer headlamp covers (red, yellow, blue, etc., lens covers) are not legal to use when you are riding within a highway right-of-way, or during the hours of darkness. Under most circumstances, you cannot use colored headlamp covers.
Your snowmobile must be equipped with at least one brake, operated either by hand or by foot.
Track studs or cleats are legal to use in Wisconsin without paying additional fee-pass requirements. However,use common sense and recognize when studs are used improperly or aggressively they can damage property
and can tarnish your image, which makes it diffi cult to
maintain existing trails.
Your snowmobile must be equipped with side marker refl ectors if manufactured after July 1, 1972.
Your snowmobile must have a muffler in good working order, which blends the exhaust noise into the overall engine noise to prevent excessive or unusual noise. The only exception to the sound laws are when you operate your snowmobile during a Sanctioned Race or you are a
dealer/manufacturer testing the snowmobile on your own land.
◆ Noise limit—82 dBA for every snowmobile manufactured and offered for sale or sold in this state after July 1, 1972 and up to July 1, 1975.
◆ Noise limit—78 dBA for every snowmobile manufactured and offered for sale or sold in this state after July 1, 1975.
The department is adopting a new rule for testing snowmobile noise. To help stay compliant, do not alter your exhaust to be louder than the original exhaust system. If your snowmobile sounds louder than normal, you may be in violation. Maintain your snowmobile and seek the advice of a service technician if you are in doubt. You cannot modify your snowmobile’s exhaust in any manner that will amplify or increase the total noise emission above that emitted by the snowmobile as originally manufactured, regardless of date of
manufacture.
Excessive or unusually loud snowmobiles are illegal and
hurt Wisconsin’s trail system. Do not increase your
exhaust noise or operate with your exhaust system in
excess of the sound limits. Wisconsin vigorously enforces the sound limits and penalties can be severe, however the worst thing about a loud snowmobile is that it causes properties to be permanently closed to snowmobile riding.