03 WR450 exhaust

Hey guys I have an 03 WR450 and was thinking of trying an aftermarket exhaust to juice it up a little, but don't have the first clue as to what to look for and who gives the most bang for the buck. The FMF /w power bomb looks really nice but I'd be kidding myself if I was saying the decision wasn't based on aesthetics alone. I ride New England trails (pretty technical stuff) and spend most of my time in the woods on private property so I'd like to keep it as stealth as possible even tho I ride mostly with the stock pipe uncorked.

Any suggestions? what works for you guys?

My 04 WR450F woke right up, after I installed the factory YZ pipe (ebay) and added the PMB quiet insert. Hell of alot cheaper than any of the aftermarket set-up's. But it's your money.

I did have to re-jet, but the difference was night/day.

If you go this way, I have a Dr. D endcap/SA and quiet insert that has about 4 hr. on it for sale.

how much does the PMB insert make? I hear the YZ exhaust is really loud, I'm trying to make it more stealth and bump the power if possible in the same shot.

FMF Q. 98 db. Works great. A little pricey.

Just the slip on? I was entertaining the thought of a new head-pipe as well, They claim PowerBomb is supposed to be quieter and deliver more power...

any clear advantage?

If noise is not an issue, any of the mx pipes are the best choice. They make a ton more power than the "quiet" pipes.

Riding technical places, you might want to look at a long header set up, as this gives you bottom to mid.

A lot of people here really like the fmf powercore muffler, the new Ti version looks great.


Noise is a huge issue. Living in CT (with the exception of Thomaston Dam) there are no legal riding spots. I mean yes we have to register and pay taxes but after that we are still considered criminals around here. So private land (yes with owners permission) is the gospell around here. I swear this is the worst state for the best sport. :thumbsup:

So i need to setup to be quiet so:

1) No one calls the cops since it's so noisy.

2) I can hear the kids on 2 strokes that ride (without permission or sense of direction) on that land

3) low profile is my thing I want the power of the stock wr uncorked (at least) without any of the noise

Think WR Ninja... The mega bomb header looks sweet too but -1.5db for 300beans is just crazy talk. But it is cheaper than entertainig the thought of the new aprilia 550/450 fi twin.

I have a stock aluminum '05 Yamaha WR450F muffler that you might want to consider. It has the "pleasing asthetic looks" of the aftermarket mufflers, but is much sturdier and better built. I bought it for my '04 WR dual-sport project(which it fits by the way), but never got around to using it. The muffler is in perfect condition and still has the orignal, very quiet but plugged up, "inner" baffle in it. If you choose, you can remove this tiny "inner" baffle and run just the "standard" baffle as most WR owners due, and still be below 96db.

Send me an e-mail if you're interested and I can send you some pictures if you'd like. I'd ask for $85 plus shipping (probably around $15).

Good luck, -Neil

I wonder how tough figuring out the jetting would be on that setup (05 muffler on an 03) I'm still fighting a little bog and popping in the hotter months when I back off the throttle. I'm still a little intimidated by my carb, but I'm gaining a little courage. Doesn't the 05 have a new "squish header and compression" and stuff I'm not about to pretend I understand, yet.

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