Best Pipe for 04 WR450?

Just got my 04 WR450 and it is sweet. I have done all the free mods and pulled the exhaust insert. I am wondering if anyone has any advice on aftermarket pipes that work the best for the bike. Mostly riding desert and trails. I am interested in the FMF and the Yoshimura pipes. Any advice would be greatly appreciated.

Life get good when you open it up!

Check your PM's.

Hey, we are also interested. Please share. :)

I am running a Thunder Alley ceramic coated pipe with the spark arrester core and a self made insert to try and quiet it down some. Performance is great from bottom to top. It weighs about 6 lbs. less than stock. It is too loud though. About the same if not a little louder than the stock pipe open. I have ridden with guys running both the FMF Q and the Yoshi quiet pipe. They seemed very quiet compared to mine and both guys said they were happy with the performance gains. I didn't ride their bikes to compare to mine but liked the noise level. If I were to buy another pipe I would try one of those.

:cheers:Lowedog

Where I ride there are noise issues so I stayed with the stock pipe on my Canadian WR450. The cops now have an atv patrol in our main riding area and will ticket anyone over 96dba. I must be getting old because I find it annoying to have someone show up with a full race exhaust system that blows over 105dba and then blasts around on the fire roads all day but as soon as they get onto a single track even an old out-of-shape fart like me can just smoke em. Just call me a crumudgeon.

I also ride in Michigan from time to time and while the stock muffler does have a spark arrestor it is not marked as being US Forestry Approved. This is probably the only reason I will be changing the exhaust system this winter to something like the FMF Q system.

willy fitz

I've got a PC496 and really like it - it delivers good power and is 96 dB!

I am running the white bros. e-series on both my 426 and my sons 250F. I like the e-series because it is cheap, light, and tunable. Right now, I am running the silent core ($35 extra)insert, all 12 disks, and spark arrestor. This should be right at 96 db. If it is not, it is easy to get the sound down by removing disks. If you go down to 5 disks, the sound is much lower. So bottom-line, if it is too loud, you can make it quieter right on the spot with an allen wrench in about 3-4 min.. The silent core is also easily removable in 3-4 min. In addition, you have different rules for track and trails. So, if you go to the track, in 3-4 min. you can take off the disks, silent core, spark arrestor, put back the end cap and viola you have a YZ straight through pipe for a little extra power. Hard to beat that flexibility. Look at my sig. for jetting. My sons bike is fine with the stock YZ jetting. Good luck with choosing a pipe. There are alot of good ones out there.

You say the 'e' series is cheap. What did you pay for it?

I am going to pull the baffle out the stock wr '04 pipe this weekend. A dealer told me that there won't be enough back pressure and may damage the engine if I do it. Is this true? I thought this was one of the free mods. Which other mods should I do at the same time as pulling the baffle? :)

The dealer is wrong....maybe an idiot. Don't worry about it. But, you WILL have to re-jet for it.

The dealer is wrong....maybe an idiot. Don't worry about it. But, you WILL have to re-jet for it.

That's what I was thinking.

:)

What is the difference in power between the PC96 and the stock pipe uncorked? Also is there a big weight difference. I looked on the Pro Circuit site but they don't even have the pipe on there yet. I checked it out at the shop today and it looks really clean. Thanks in advance.

I ran the stock pipe without the cork (and re-jetted) for my first 400 miles. I have had the PC496 on now for the last 500 miles - the power is at least as good and maybe better. The instructions are poor – no clamp is needed to attach to the front header pipe and you'll need to buy the YZ muffler upper mounting grommet and longer bolt. I also re-jetted again. I really like the pipe - its lighter, looks/fits great and meets the 96 dB requirement, but is expensive.

Does anyone have the Yosh Stainless Steel "Competition" System or the Titanium "Pro" Slip On on their WR426?

Does the above information for the WR450 also apply to the 426?

I want to by an exhaust system also. Just want to keep it somewhere between the stock uncorked and the baja design insert noise level. This way I hope to get improved performance and not piss off too many folks with noise. Plus I am set up for Dual Sport for the occasional trip downtown.

A dealer told me that there won't be enough back pressure and may damage the engine if I do it

.

A wrench at a dealer near me said the same thing to me and was not sure if it was true or not :).

Smoke :D

A dealer told me that there won't be enough back pressure and may damage the engine if I do it

.

A wrench at a dealer near me said the same thing to me and was not sure if it was true or not :).

Smoke :D

If that was the case, every YZF out there would have burnt valves....it's an "Urban Legend"/old wives tale/or just an idiot repeating BS he was told by another idiot :D

Hey jbodily, I've got the yosh stainless comp system on my WR 450 and I love it I also have the power now installed and the two together make things happen :) . I dont know what the decibel level is with it but I got the TEC kit with it for those hosh hosh conditions.

Thanks bigdaddy450. Right now I use the stock pipe with a Baja design insert when I need it quiet and uncorked when in the desert.

This may seem a basic question but does the Yosh really change the power that much from running the stock uncorked?

I thought so. I was running the stock pipe uncorked before I put on the yosh system,of course I tried it out before putting the power now in and I noticed gains all through the rpm range, Im very happy with this system and would recomend it to anyone :)

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