WR450 Exhaust Insert

10 replies to this topic
  • Poway Rider

Posted April 30, 2003 - 05:05 AM


I'm looking for a new exhaust insert for my WR450. The Pro Moto Billet (PMB) insert looks good. Has anyone tried the PMB insert and did you like it? Any other suggestions would be appreciated. I don't want a new muffler, but an insert that will keep me legal. Thanks

  • beezer

Posted April 30, 2003 - 05:48 AM


I gots me one of them.

They be nice.

Better then da GYTR.

  • ColoradoTim

Posted April 30, 2003 - 05:55 AM


The GYR insert looks like the best bang for the buck at $38 and keeps the sound to 96db. But that's not what I did because I have a Canadian bike with a welded on plug.
The solution I used cost under $70, will work with US or CAN bikes and can be modified for sound/ power within a few minutes. It's also USFS spark arrestor certified. It's the old SuperTrapp solution.
Cut off the end of the muffler along the inside (towards the engine) of the weld. Saw off slowly as stainless steel cuts better that way. Tap in a Supertrapp 4" standard insert, part way(cut off part of the screen so it will go in the muffler), mark the three holes, remove the insert and drill the holes. Reinstall the insert and bolt on. I use 6 disc's and it is a reasonable compromise between sound and power. More disc's for closed track and less for quiet. At 4 disc's, the power suffered a lot.
I bought my parts at mxsouth.com:
#10-772 Pro series core kit $33.50
#10-770 Diffuser Disc 4" 6 pk (comes in a 12 pack too)$15.09
#10-423 Strpp Stnls end cap 6bolt (spark arrestor) $17.25
Buy the bolts (US)at a hardware store for about $5.
This will work for 2001 to 2003 WR's as I have done this to only those years. As long as it is a standard 4" pipe, the insert taps in perfectly.

  • Poway Rider

Posted April 30, 2003 - 07:10 AM


Is the GYR insert you mentioned the same as the GYT-R from Yamaha?? Thanks :)

  • tigerowner_ut

Posted April 30, 2003 - 08:08 AM


He is refering to the Yamaha insert. The PMB is the best way to go. It flows better and has the same noise output. I heard a reported 92db for both the PMB and GYTR

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  • Poway Rider

Posted April 30, 2003 - 08:09 AM


Thanks, I just ordered one.

  • GravityChallengd

Posted April 30, 2003 - 10:12 AM


Can anyone give me a link to the PMB insert? My dealer tells me the GYTR part is back ordered until the end of June. The stock insert broke (the welded tab holding the nut snapped - I don't know how, I've fallen only to the left :) ) and it's way too loud without it.

  • curtis916

Posted April 30, 2003 - 12:05 PM


I use the PMB insert and was (un)lucky enough to be tested at Stonyford last weekend, the ranger said it was 93db and that was ok. My 03 WR450 runs better without it and with the insert it backfires on hard decel (pop).

  • PeakRider

Posted May 04, 2003 - 02:48 PM


I put a PMB insert in yesterday, now my 450 feels like a 125. I had been running a YZ426 with PMB & quiet insert so I'm very disappointed with the performance decrease.

  • Tom_Rowlee

Posted May 04, 2003 - 03:54 PM


I have a pro moto insert in my wr 400 and it runs great 'the low end seams to be the same don't realy know how much it hurt the top end but i ride tight woods so low end is what im interested in . At first i thought the power was down but i think that was because the noise level is a lot lower and most of us think that noise = power .In theory more back preasure should increas low end to a point , you may need to re-jet thought. [Just my opinion]

  • curtis916

Posted May 04, 2003 - 07:51 PM


Here is the link www.promotobillet.com


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