WR Muffler on a YZ?

My buying decision for a 2007 YZ450F hinges on the answer to this question:

Can the WR muffler bolt right on to the YZ? (2007 model)

I have acreage but I also need to be considerate of the neighbors and I don't mind the minimal loss of power with this "reverse" mod.


It should fit. Previous year models were interchangeable.

How much quieter is the WR muffler than the YZ?

A lot. A stock '07 is around 95-96 db (I believe), and a WR is at street legal levels, which would have to be closer to 86 db.

A current FMF Q comes in around 92 or less, which is not "that" loud, really, and would be a lot cheaper.

You might get a WR guy looking for inexpensive power to swap pipes with you.

Thanks Gray, I guess that I will check out eBay for a '00 WR 426 muffler and just repack it if necessary.

I've got a full 07 WR exhaust I'll sell ya for the cost of shipping and a hamburger. From what I remember, the mufflers are not interchangeable but the full exhaust is. I might be wrong this is just what I remember from my research a few months ago.


I don't think the WR426 exhaust is much quieter than the YZ426 exhaust. The 07-08 WR pipes are the ones that are functional and super quiet.

But will an 07-08 WR exhaust be a direct bolt up for an '00 YZ 426?

It would be great if so, but I rather doubt it because the frames are completely different and would guess that the mounts would be completely different as well.

But will an 07-08 WR exhaust be a direct bolt up for an '00 YZ 426?
Nope, won't fit.

I just fitted a wr250 03 silencer to my yzf450 03, i started it in my garage and it sounds like a giant sewing machine, very quiet and will pas MOT over here for road usage now. Gonna test ride it at track next weekend.

I would not waste my time putting the heavy, corked up WR muffler on a YZ but to each his own. I would much rather spend the extra $ for a decent slip on.

im with cowboy

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