FMF Q muffler vs the stocker

I run the stock exhuast with a gytr insert. When I run it open with no insert, it makes it alot more snappy. But it's probrably too loud for most riding areas. Does the fmf q run just as hard as the open stocker?

Do you guys recommend any other mufflers that make decent power, but aren't too loud?

Also, after I rejet it for the open muffler. Will it run like a turd when I have to run the gytr?

I have run a Q on my 03 WR450. It made me feel like I had to shift more often than when I run the stock system open. It's way better than the VOR tip I have though.

I used a FMF Q on my 02 426 at both high elevation and at sea level. The one difference I noticed was the missing bottom end at both places. It really killed it at high elevation but also knocked it down pretty good at sea level too.

I've got one on my 2001 WR426. I tried the open stock exhaust and it was just too loud. Then I bought the GYRT insert and I think it sucked. Next I tried the PMB and it was a little better.

The FMF Q runs a little better than the open stock exhaust in my opinion but it is still a little on the loud side.

I have the Q on my 03 WR450 and love it!!

I doesn't run quite as good as the open stock exhaust, but not enough different to call the performance poor or bad. It is run MUCH better than with the PMB insert, no doubt about it!

I've passed sound tests at the last three GNCC's and it seems to have gotten quieter the longer I've had it, although as the packing begins to burns out, I'd assume it will start to get louder again (bell curve).

The quality is good as well. It is important that we all lean towards quieter exhaust systems for very obvious reasons!

I run the "Q" and love it. Jet it right and it'll run great. I have run my bike for three years with the uncorked stocker and for one year with the "Q". I don't think there is any significant loss in power over the uncorked stocker and it is way better than any of the "cork" type solutions out there. It alters the power distribution slightly but not in a negative way and in no way feels less powerful overall than uncorked stocker. I still think that a lot of people feel slower without the excessive noise of uncorked. A lot of the perceived power loss that some people claim is either jetting issues or is just plain mental. :thumbsup:


A little further on my impressions of the FMF Q. I felt like the power in the middle was about the same as uncorked but the power down low and up high dropped off much quicker than uncorked, hence my feeling I had to shift more often. My bike was/is jetted correctly when I ran it and it's not in my head or an illusion caused by the sound. I have well over 1000 miles on my Q and have had it in a many enduros, (long course A loops). So I have a very good feel for it. Now in my opinion it is the best legal option out there (uncorked being not legal in many areas).

I've been interested in a quiet exhaust but am going to wait on this generation Q ... heard the next one will be out soon and be super lightweight (all Ti?) and possibly better performance, I would imagine.

I've been interested in a quiet exhaust but am going to wait on this generation Q ... heard the next one will be out soon and be super lightweight (all Ti?) and possibly better performance, I would imagine.

Thats great to hear. I know the manufactures will figure this stuff out eventually so we can have good performance and low sound. Just need some time.

Do you know when? Because I will wait. I'd like something quieter, and that would meet the 96 decible limit.

Also, after I get the jd jet kit. Will jetting for the open exhaust make it run crappy for when I have to run the insert? The only other thing I haven't done yet is the bk mod. I'm to chicken to drill and tap such an expensive carborator. If there's anyone in the mid mich area that would help me out, let me know.


Don't wory about it. Do the BK mod, it is worth it and it is easy to do. A drill and a tap are pretty easy to use. A drill press would be best but I didn't have one and it came out just fine. Just choose your drill/tap size don't want to go to big.


You drill and tap a tab on the outside of the carb. Not the inside. I used a 4-40 tap with a bolt and a nut to secure the bolt when I found the right setting. It's very easy and I had the same concerns as you do before I looked at the procedure.

I still wonder if the FMF Q would pass a 96 db test. Mine seems louder than this.

Mine has passed it at the GNCC races this year.

It does seem a bit louder to me than 96, but it tests just fine . . . it may depend on the type of testing method though.

I have had mine tested 3 or 4 times passing all the test with no probs.

Like Kentucky, I have had my Q tested several times and passed (yea OK maybe it was right at the limit). I agree the difference between fully unplugged and the Q is minimal. I do think you feel faster with more noise, but noise means less riding in CA so quiet it is. :thumbsup:

I have a 3 month old "Q" and it is much quieter than a stock yz pipe, forget about an uplugged stocker.

Remember you have to repack these things or they can get very loud.

What have the Q's been testing at noise wise? I'm curious about how much margin a new Q has.

How much lighter is a FMF Q than a stock WR exhaust? In my case it's a '99 - black, not polished stainless.

Anybody got any experience with the 92dB silencers - CRD, etc?


I have been tested from 94 to 96 DB. Most guys are saying around 96. There is a difference between the stock (03 WR450) and the Q in weight, with the Q being lighter but I don't have exact figures on it.

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