Too Loud?!!

I have an 03 wr450 with all the free mods, and a few extra. I bought the bike used, it came with an FMF power bomb header and YZ muffler. I pulled the muffler and installed a Pro-Circuit 496 spark arrester to be legal in the woods of Michigan. Last fall at a CCC sponsored ride where they check sound levels - I failed! :naughty::D After a little southern engineering, we were able to get it close enough that they let me go. Does anyone have any experience with this combo and sound levels? How about other exhaust systems which will keep the performance but not keep me above Michigan's sound laws? Thanks for your help


whats the db for the sound level out there? 96,94?

94 db. which is pretty tough. Especially when the sound check guy is using a hand held tachometer tool and the guy who is measuring the sound levels isn't exactly sure how far away from the pipe he is supposed to be! :naughty:

Can't get my bike under 100dB without that damn WR insert for the GYTR exhaust. I wrapped so much packing around the spark arrestor, it barely fit into the silencer. My bike runs better without the insert, but I am taking it to the rites of spring ride next month to pass sound check.

What was the reading on your bike that the CCC was getting???

Try to find a new 05 muffler it flows pretty good and will meet your 94db level. Noise equals power but you cant ride because your too loud, riding is still better than not riding at all. My YZ pipe with a PMB tip was tested at 96db with some mods maybe it could pass at 94db? Its just nice to know you can go ride and pass any test. Good Luck.

I think I was right around 100 also. We took the spark arrestor off and welded a washer inside the cone, put a little more packing in and I was around 96 so they let pass - that time! I'm also planning on the rites of spring ride and don't want to run into the same problem again. It would just be nice to know for sure what works. Testing seems to be the issue. I hand held tach can allow the rpm to vary so much while taking the sound reading that inaccuracy is almost inevitable. I have thought about setting my idle up for the sound test to make sure it is accurate, but don't have a way to check rpm, nor am I sure what rpm they use to check the sound level. :naughty:

Maybe we'll hook up at ROS and share sound check woes!

I run the Yoshimura RS-3 Comp full system with the 94 db insert on my 2003 WR450f. It passed sound inspection testing at the trails near Baldwin, Michigan last summer.

I previously had a FMF PowerCore slip-on that seemed to be really loud, packing blew out after one season of riding. The Yosh system allows the use of 3 different exhuast plugs for different db ratings. This is called the TEC kit. It was an additional $40, and the full system cost around $400. Great performance gains when installed with a JD jet kit.

I run a FFM powerbomb SX and Q on my 00 400. I just barely pass at 96 here in CA with the same tyope equip. Been tested 4x and was 96db each time.

I think even with the GYT-R insert, the WR will still be too loud here. Its rated to knock the bike down to 96, not 94dB.

I may have to skip out on the CCC rides this year. :naughty:

I just don't want to put a new exhaust system on the bike if I don't have too. Too bad it's not a Harley, they seem to be exempt from noise violations.

Hey, anyone got an old Harley emblem? :naughty:

I run the FMF Q w/ the powerbomb header. Good power and under 96db. If you get the older 2004 and below model (NOT the new 2005 unit with the sealed rivet end cap) you can easily remove some of the internal sound restrictors to open it up when you want. Basically I have an "opened up" cut short version thats also drilled internally and an added screen spark arrestor out on my WR280 and a stock FMF Q on my WR400. :naughty: Yea, I'm a little type A.

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