I am looking for a recent or past issue publication that has an after market exhaust test for the YZ426F. I own a 2000 model and am currently shopping for a good after market exhaust that will give the bike more low-end grunt, improved midrange and still be able to race at the local track (sound levels).

The local track has recently started enforcing sound levels on the four strokes machines.

The only mag that I have seen that had a 426 pipe shootout is the Aug 2000 Dirt Rider. You might be able to backorder it.

Sput, if your having to deal with a sound issue, the best pipe is the one on your bike, the stocker. Just about every pipe out there is louder than stock and the stock one is louder than the AMA limit.

FMF Q might be the ticket ... I never used one though so I can't be sure.


Without expressing any opinion of my own (my pipe is stock), MX Action said the Dubach pipe was the best for the 426. I don't recall which issue it was in, but it's been quite a while - perhaps before the introduction of the Thunder Alley pipes.

I also read in one of those mags (probably have it in the garage) that Dr. D's pipe was the ticket and most other manufactures were attempting to duplicate Dr. D, I dont have one (wish I did) but thats what I read.

Oh yeah I rode with a guy who has a Yoshimira (spelling?) pipe and It shakes the earth with a low rumble, dahm was it loud. :)

Ive got a bud with the fmf Q pipe. That seems pretty quiet.

I have the FMF Megamax II. It seems quieter than stock. And Its tunable for less sound with the disks. However ive been told that in order to get it to pass the 94db for Michigans trails that you need like 2 disks at wich point it wont run. Ive been told by others that my megamax seems quieter than stock.

Just my 2 cents.

I was thinkin of addin the powerbomb header. I heard that that can mellow it out a bit.


What is the DB level they are enforcing??? Do the 2-smokes meet this requirement???

I recently trashed my e-series and put the stocker back on (with a promot billit s/a) and sometimes I'm not sure if the thing is even running.......Next time I will follow ShawnMC's advice and go with a Thunderalley......

When you do get that aftermarket pipe that has a low DB level let us know what ya think of it...good luck jt

I've located and use a Canadian YZ muffler. It's about 50mm longer than a stock 01. I should test both pipes back to back but have not done so yet. I bought the pipe for riding nearby my house. It is definately quieter than the shorter pipe.


I don't have a YZ-F, but a friend that I ride with does, a YZ400F. He changed from a Big Gun to FMF Q and it is much quieter.

About a month ago, I helped doing sound checks at an enduro. The 400 plus cc 4 strokes were the ones that had trouble meeting the 101 db limit. Most of them just barely made it under the limit. KTM's had no problem with stock exhaust. The 2 strokes had no problem unless the silencer packing was blown out.

July DirtBike has a shootout of pipes for the CRF450. Dyno graphs, rider impressions, BUT NO SOUND LEVEL READINGS!!! I guess that they don't want to offend their sponsors.

Ride on


I've done alot of research on the subject. 02 YZ header and silencer combo are the best you can find. I put them on my 99 WR and absolutely LOVE IT!

Mr Toyz

I have that issue in my stack and I am still lookin for a scanner to post the 450 brochure and as soon as I find one i will also post the issue and tests.


Go with the FMF Q. Make sure you go with the power bomb header combo. I've tried the Q with stock header and did not like it. With the header, It changed my mind

I love my DRD & I have never had any issue with sound test at the tracks.

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