I got the same problem let me know if you find a good solution.

I'm running water through them. I have baffles in them that were purchased from CP Performance they are part #410-284402 HP Silencer. The sheriff tested them with a meter but I looked up the law and it says that the test shall be done 4 feet back from the exhaust at idle, my idle was a bit high that day. He was nearly in my pipes when he took his reading. They tested at 125 decibles, legal here is 89db I believe. The DNR officer never even heard it run, he was going by a complaint that he got of a loud boat.

When I was told I was too loud, the first words out of my mouth were I have baffles in them. He did not care. He stated that the fine would be $300 and he could ban me from the water until I make my boat legal and have it inspected & tested by a sheriff.

Minnesota Stationary Idle Test. Taken at least 4 feet above the water and at least 4 feet behind the transom of the boat. 86 dBA... Looks like I will have to go the tt route.

Also make sure you're running water through the headers when they test it. At idle, typically, there should be no water. If running a driver mounted valve, open it up some for the test 

If just the Basset T valve, shouldn't have water at all til around 1500 RPM, but you can open up the gate or ball valve on the outlet to the engine from the pump. If the pumps fresh or good, it'll open that valve all the time usually. Worth a shot.

I don't think you're gonna get to 89 Db with O/T headers at all though. Possibly with some of the Borla style mufflers out there, I dunno.

Ray

He's not running headers! He has logs!

I wonder what an msd 6AL with a very low rpm chip would sound like.   
Probably wouldn't work but if it did that would be a nice trick.

This is just a prime example of the gov. out of control.   Someone sits behind a
desk and decides what you can and can't hear.

Beauty is in the eyes of the beholder.

I think they sound beautiful but the gov. won't let me hear it 

You think something like that would get it low enough being measured at 4'?

These laws are out of control!

Wait a minute....I just realized something. You mean to tell me the state that prides and promotes itself on being the "Land of a Thousand Lakes" has serious issues with loud, classic, original boats?  Theres a double standard!

I understand they're as bad in Florida, which I don't get as well since the vast majority of residents wear hearing aids anyhow, but REALLY?

This world is FOCKED UP!

Ray

You think something like that would get it low enough being measured at 4'?

These laws are out of control!    You guys are being had   

Measuring the sound at 4' has to be the dumbest thing I've ever heard.   Who in their right mind would come up with a regulation like that but an idiot paper pusher.

 Anyone within 4' of the back of my boat that would be offended would already be drowned.    

You would think it would be measured from at least 50'   Notice the Deisel truck listed below, they are on the street every day,  right beside a lot more people than will ever be exposed to boat exhaust.  It's higher and measured at 30'. 

I wonder why they didn't tell them to muffle it 

That enforcment level and distance is just insane and is nothing less than harassment 

Some average levels are listed below.
 Threshold of hearing
 0 dB
 
 Motorcycle (30 feet)  Here again, everyday exposure by anyone on the side walks
 88 dB
 
Rustling leaves
 20 dB
 
 Foodblender (3 feet)  Funny this can make more noise than the human can bare from a boat engine!
 90 dB
 
Quiet whisper (3 feet)
 30 dB
 
 Subway (inside)  Good lord!  How can these people stand it.  They'll all be deaf 
 94 dB
 
Quiet home
 40 dB
 
 Diesel truck (30 feet)   
 100 dB
 
Quiet street
 50 dB
 
 Power mower (3 feet)    Shut them down!   
 107 dB
 
Normal conversation
 60 dB
 
 Pneumatic riveter (3 feet)
 115 dB
 
Inside car
 70 dB
 
 Chainsaw ( 10 feet)
 117 dB
 
Loud singing (3 feet)
 75 dB
 
 Amplified Rock and Roll (6 feet)
 120 dB
 
Automobile (25 feet)
 80 dB
 
 Jet plane (100 feet)
 130 dB
 

Typical average decibel levels (dBA) of some common sounds

I'm running a BBF 460ci. with Hardin logs and Rewarder over the transom pipes with baffles. I have been told by a sheriff who tested my decible level that my boat is too loud so I got a warning ticket & I also got a warning ticket from a DNR officer. I'm tempted to buy some used snails & run my exhaust through the transom. My boat has never had threw transom exhaust. Any help with my issue will be greatly appreciated. I really want to get on the water but I do not want a $300 fine. If someone has some used snails they want to sell I might be interested or if anyone knows of a baffle that will get me in the legal range that would be great. Thanks.

Did he show you the decibel meter after testing or just tell you that it was too loud?? 

Minnesota's boating noise laws   http://www.boatus.org/onlinecourse/statelaws/Minnesota.html

"An effective muffling system in good working order is required for the exhaust of each boat engine. This system must be effectively installed to prevent excessive noise. Loud boat noise not only bothers other operators and users of the waterways, it can also disrupt peace ashore because of sound's ability to travel great distances over water.

Excessive noise can also prevent you from hearing other boats' sound signals and warnings, and approaching law or rescue personnel. Specifically, it is unlawful to modify, equip, sell or operate a motorboat that exceeds the levels indicated below.

Specifically, no boat shall be operated if it exceeds the following noise levels:

•Boats built before January 1, 1982 must not exceed 84 decibels (dBA) during a pass-by test or 86 dBA measured during a stationary idle test.
•Boats built on after January 1, 1982 must not exceed 82 decibels (dBA) during a pass-by test or 84 dBA measured during a stationary idle test.
A Pass-By Test is usually taken at 50’. An equivalent reading may also be taken at other distances. A Stationary Idle Test is taken at least 4’ above the water and at least 4’ behind the transom of the boat."


Make sure you see the actual DB meter reading and make sure he is standing the 4 feet back.  Get a copy of MN's staute on this and keep it with you on the boat for next time.  That is if you are within the DB. 

Boy am I gonna be popular when I put these Zoomies on sumpin......

Ray