This is the Ohio law which Michigan is trying to mimic along with the legalization of the new "Noise Gun" with the added changes to J34 maximum allowable decibels (70 at 25 meters idle and 86 decibels at 25 meters full power).

OHIO LAW

Exhaust Muffler Required: Effective January 1, 2000
Every powercraft operated on the waters in this state shall be equipped at all times with a muffler or a muffler system that is in good working order, in constant operation, and effectively installed to prevent excessive or unusual noise.


No person shall operate or give permission for the operation of a powercraft on the waters in this state in such a manner as to exceed a noise level of 90 decibels on the "A" scale when subjected to a stationary sound level test as prescribed by SAE J2005.

No person shall operate a powercraft on the waters in this state in such a manner as to exceed a noise level of 75 decibels on the "A" scale as specified by SAE J1970. Measurement of a noise level of not more than 75 decibels on the "A" scale of a powercraft in operation does not preclude the conducting of a stationary sound level test as prescribed by SAE J2005.

No person shall operate or give permission for the operation of a powercraft on the waters in this state that is equipped with an altered muffler or muffler cutout, or operate or give permission for the operation of a powercraft on the waters in this state in any manner that bypassed or otherwise reduces or eliminates the effectiveness of any muffler or muffler system installed in accordance with section, unless the applicable mechanism has been permanently disconnected or made inoperable.

No person shall remove, alter, or otherwise modify in any way a muffler or muffler system in a manner that will prevent it from being operated in accordance with this section.

No person shall manufacture, sell or offer for sale a powercraft that is not equipped with a muffler or muffler system that prevents noise levels in excess of those established in division (B) (1) of this section.

Here are some of their comments on the new gun.

The noise gun is user friendly. All functions recording sound and distance from a suspect boat, are automated. It compensates for envronmental conditions: ambient (background) noise from nearby watercraft, wind, reflective surfaces (docks, etc.) Officers only need to point the device at a target boat for a sound level recording which can be used as evidence in a court of law. Thus, problems of current enforcement, which require cooperation of the suspect boater under complex, controlled test conditions, are simplified. As the noise gun’s trigger is depressed a uni-directional microphone, sensitive to only narrow beam of sound and a laser range finder are integrated to provide a continuous reading of noise and distance to target boat.

The test runs revealed that the target boat’s bearing is important. The Elliott boat was equipped with a “captain’s choice”, an option to run the engine with or without a muffler. Unmuffled boat noise increased from about 90 decibels at closest passage to about 97 decibels as the boat was going away. The test demonstrated effectiveness of the boat’s muffler. Despite 10-15 mph ambient wind noise the device-achieved measurements over a wide range of distances with accuracies of better than 3 decibels.

Roscommon County Sheriff Francis Staley, and Antrim County Sheriff Terry Johnson each operated the noise gun which they found very workable and were able to make repeat measurements of the test boat’s noise, an essential for successful wide usage.

So if i'm in violation how will they catch me?? Let's Rock.

Vhf radio or cell phone!!!!

My brand new honda push mower is 94 db How long before the courts make me put another muffler on at my expence. They should make the dealers comply not the owners. I spent two grand on mufflers for my fountain and it still will not pass. so, I quess it will be ticket time and how many of those will it take before they throw me off. They might better take our birthdays away while the a$$ O's at at it.

Just another reason to make sure you vote these fools out of office for pushing a law like this

What kind of mufflers and what is the current decible level? My belief is the law is challengable if the technology does not exist to comply. As some have stated, outboards will not pass and almost all of the patrol boats over here have one or two big outboards. I am just looking to make sure whatever mufflers I change to are the best available so I do not ever have to replace them.

Best post in this thread. Fax, call, e-mail these politicans and let them know when comes election time you will campaign to un-elect them.

CMI Sound Elimination System Muffers work, we have tested them on 1400 HP engines. They switch on their own so they are legal.

Ask Brad Zastrow. They got him legal for the stationary test.

"Every powercraft operated on the waters in this state shall be equipped at all times with a muffler or a muffler system that is in good working order, in constant operation, and effectively installed to prevent excessive or unusual noise.No person shall operate or give permission for the operation of a powercraft on the waters in this state that is equipped with an altered muffler or muffler cutout, or operate or give permission for the operation of a powercraft on the waters in this state in any manner that bypassed or otherwise reduces or eliminates the effectiveness of any muffler or muffler system installed in accordance with section, unless the applicable mechanism has been permanently disconnected or made inoperable."

I'm not sure they would be legal under the new law, if approved. My belief is that many of the new systems would pass the old standard of 90db at idle at 1 meter. But 70db at idle at 25 meters, 86db at full throttle at 25 meters and 75db from shore or any stationary object? These are the new J34 standards.