Making your stock muffler shorter???

I was thinking about cutting off about 3" of my canister on my stock muffler...what got me tinking this is I bent my muffler in a recent crash. And I saw this picture yesterday:


Have any of you guys done this (obviously this guy did since that is a stock muffler and it is short)? I was thinking since I already have a new R4 on my stock muffler is just laying there all bent up, do you think modifying it would help it tuck in better, or better bottom end, louder, etc? Cause it looks like you would just have to drill new holes and re rivet it after you use a bansaw to cut the canister! Thanks for your input!



I get my kicks on a 2001' YZ426!

Friendswood, TX

[This message has been edited by motoman393 (edited 02-23-2001).]

I used to do it for my YZ 250(2-stroke). For certain tracks I used the shortened silencer for amazing tourqe gains. But for fast stuff, I ran a standard length silencer. Don't know if this theory works for the 4-strke, but it was night and day on the 250! Hope this helps! Later!

Hey since your old muff is just sitting there and is still in one piece you have a great opportunity to have a modified stock verses a R4 test. You could cut 1 inch off then run them back to back with the R4 then 2" then 3" and give us a good seat of the pants report, noise, torque,over rev, & etc.


yeah that is what I was planning on doing (I even got a new exhaust gasket on the way)! The stock muffler is already great but it could have more bottom (so you can bog it around the track like on the R4) w/little sacrifice on top! I already measured my R4 canister and a WB shorty canister and have made marks w/a pencil on my stock one...all i need to do is start hacking away! LOL


that could be a white bros e series with the curved end cap in the pic

no...that is a stock muffler because the dump tip is integrated in by rivets (look closely) and it also doesnt have the e series logo! And it is also a tad bit shorter than the WB



I get my kicks on a 2001' YZ426!

Friendswood, TX

For a car. The less back pressure you have the more top end you will get. I would guess that this would be the case if you shortened the stock exhaust.



01 YZ426F #85 Vet C

I agree , My buddy just bought Pro Circut System for his 2-stroke (3in shorter)& he says it has more on top. My 426 has Eseries shorty & it did not help bottom but it feels better on top.

i have the wb pro meg and it looks exactly the same INCLOUDIND THE RIVETS and the length

[opps you were right i took a closer look and i could not see the mounting bolts as on my wb end cap it must be stock shortend mine does have the rivets though

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