Need to meet 96db limit as cheap as possible!

I recently purchased a 98 YZ400F, I love this bike and I am having a LOT of fun on it. However, it has an older FMF Powercore 4 exhaust system on it; while I haven't had it tested I am sure it is well above 96db. I contacted FMF to see if I could use the modular end cap, but it is only for the newer model PC4. I would like to find a way to quite this thing down but I don't want to spend a fortune doing it! It is only a matter of time before I get caught and I don't want to be THE GUY with the loud annoying bike anyway. Could you please give me some ideas on how to accomplish this? Thanks

find a used FMF Q for $90 like i did for my 00 426.

If you have to be at 96 db or lower, you have three options.

1. FMF Q

2. White Bros E2

3. WR stock exhaust (this is plugged and you will lose a fair amout of power)

426Hurricane - where did you find a Q that cheap?

Dano426 - Losing power is not an option! Out of the FMF and White Brothers which one in your opinion will offer the most for my money.

Thanks for the quick replies!

I also have the older Powercore IV muffler and also Hi-flo header. I'm at 104db so I would expect you're around there. I talked to some lady at FMF and she said there was nothing i could do to the muffler as is. You're best bet is to find a used Q muffler, and keep it well packed. Or find some way to put some baffling in the muffler. i've made attempts to no avail, so, good luck. By the way, this is an '02 426 so it might be a little louder.

Dano426 - Losing power is not an option! Out of the FMF and White Brothers which one in your opinion will offer the most for my money.

From what I see from the Q is that you will lose some of the high rev power - no over rev. Low to mid is still great and the powerbomb makes it even better. I ride mostly trails and a track now and then so I don't rev out the bike like a die hard MXer. When I purchased the Q I cringed at the price, but now it is worth every penny. :)

I have heard good thinks about the E2 but have had no personal experience with them.

Check out he TT store, they have good prices and may have the deal your looking for?

Tell us what you get and what you think of it


I have the E2 went from an R4, I see no differance in power or delivery in the E2 as compared to the R4 full Race. I like the E2 it is a nice looking pipe well built and you can remove the core for Private Track racing. But honestly I see no differance there acept it jumps to 107db without the core.

Get the E2 support the community :)

Well thanks for all the advice, unfortunately I didn't find a super cheap solution but I did find a deal on a Q so that is what I am buying. Thanks again.

I have a 03 yz450 with the stock pipe and a pro moto billet endcap. If I put in their quiet insert I can pass at 94db, w/o the insert I'm sure I'm still over 100db.

See if you can find a stock 03 pipe on ebay or someting and get the promoto endcap setup.


I also have the PMB endcap with the insert, and I have a really hard time believing it is under about 102 db even with the quiet insert and the SA installed. It is better than stock, but it is still loud.

I have seen several people say they failed the 96db sound check with it too...

PMB advertises the 250f quiet insert as a 96db insert and says you can pass the test with it, but the 450 insert is advertised as "reduces output by 4-5db. It never says you can meet or beat the 96db test for the YZ450.

I have already purchased the FMF Q, I rode today and was very pleased with the performance. It has more bottom end and didn't seem to hurt the mid range/high end at all. This isn't as cheap a solution as I was hoping for, but it seems to be the one that works! It was really nice not to be hiding from the rangers today and not feeling like a jerk out there. Thanks to everyone for taking the time to help me out.

I have already purchased the FMF Q, I rode today and was very pleased with the performance.

You'll be very happy with your puchase. The rangers don't even bother checking you if you have a Q :)

another note, I went from the Iv to the Q and did not have to change jetting either. very happy, slight loss of power, but it still has more than I use. I also have the PowerBomb header and passed the CA noise check.

Mik e

I have a 99 YZ400 with the Pro Circuit T-4 pipe, and i cringe everytime i fire it up in my small, quiet community, anyone have the same setup but added the "quiet core" add on? I love the pipe and dont really wanna swap it out.


99 YZ400 Street lagal

If you want to be really cheap and look like a spode, you can do what some guys do in a pinch- cut about a 6" chunk out of an old inner tube and zip-ty it to your pipe... it looks plain dumb but it works for a temporary fix.

If I were you, I would give Bob at Thunder Alley ( a call- he mades 96 dB inserts for his pipes now I believe.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now