2005 WR450 Exhaust Restrictor

Does anyone know for sure that if the exhaust restrictor is removed that the sound level will remain below 96db?

Removed mine recently and the exhaust noise increased. Don't know what the factory Db level is but I suspect removing the baffle bumps it up several Db.

that GYT-R insert won't fit the '05, because the exhaust can is different from the '04 and earlier ones. not sure what else is out there though

I would check out the Pro Moto Billet endcap for the 05',it should give you a little more power and still be quiet enough.( Here is the quote from there website:Manufactured from 304 stainless steel, the 2005 Yamaha WR Silent Insert that is more like a performance insert. Throw away the stock baffle that comes with your bike because it is simply too restrictive! Here is the solution. The silent insert simply replaces the stock baffle. Extensive testing was done to achieve maximum flow-rate and still be below the 96 db law! )

I welded up my own out of stainless tubing but I also took the baffles out so it is louder than 96dbs now. Hope that helps out some. Check them out at:


Per the May issue of Dirt Bike magazine, yes,the 05 does stay below the 96 db limit with the end baffle removed. Don't waste your money on an insert.

Just ordered an insert from this site for my 05 based on another TT member's high recommendation in a recent thread: www.quietiscool.com

I use the Pro Moto Billet on my 05 and it is definitely louder than stock. I have never had it tested but I would bet it is under 96. I ride on the street and have never been stopped.

Per the May issue of Dirt Bike magazine, yes,the 05 does stay below the 96 db limit with the end baffle removed. Don't waste your money on an insert.

Don't remove the whole baffle! Remove the baffle and then drill out the two small rivets and remove the small inner baffle. The db will be below 96 with the small insert removed but not the whole baffle. The PMB insert is the way to go but you should rejet if you install it.

Correct, the inner baffle is the one to remove by drilling out the 2 rivets. The inner baffle is installed in what is known as the tail pipe so technically there is only one baffle at the exit end of the exhaust system. It'll stay below 96 DB and breath pretty well.


Why should you worry about being stopped on the street by just having your baffle removed? HARLEYs can get away with NO MUFFLERS at all.

WHY IS THAT??????? :D


Jim, I've wondered the same thing!....Here we are trying to get under 96db to ride in the dirt and they have to be blowing well over 100 on the street!

I pulled my whole baffle and left the spark arrestor.. It's louder but not by much.. Sounds kinda weird though,, hard to describe. I like to think it made it faster.

Need to remove the stock baffle to open it up for more POWER. Go with the PMB insert.

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