Thought this would be of interest on motorcycle noise discussion:
Watching TV this am while on computer a show Wardens on the Outdoor Channel showed Michigan game wardens checking snow mobiles for noise where 80 decibels is the limit. They do this because a lot of trails are on public property and if too noisy the public loses access by the landowner.
Wish the police here were more diligent in checking motor vehicle noise. There are places here where jake brakes are prohibited to be used.