YZ 426 too LOUD!!!!!!!

Barbuster · Feb 9, 2001

I have a 2000 yz426 with an FMF power bomd header/power core 4 spard arrester.
Last sound test was 98db.
To pass sound test I need to be 94db.
Any feedback on different pipes and db readings would be a great help.

DADCRASHED · Feb 9, 2001

The 426 Stock pipe is pretty good. Why did you change it? Just about all aftermarkets will be louder

PeterEXC520 · Feb 10, 2001

Hi Kalitude,

Originally posted by kalitude:
Wow! That's quiet! My TTR125 was read at 113!
Guess I can't ride where you ride

113db? Your TTR must sound like a jet :-)
Here in Germany/Europe the db limits are 98db for moto cross and 94db for enduro. Anke's KTM EXC400 and my KTM EXC520 are about 92db (with the stock pipe). I think my Biggun will be a little bit louder but I hope not too much.
BTW Anke's first race will be in March...
Peter

http://www.gp-racing.de/widowmaker_intro.html

mgorman · Feb 10, 2001

I am a firm beleiver in sound level reduction. I don't beleive the aftermarket companies try too hard when I hear bikes with "Silencers" that are louder than harley's with straight pipes. I have heard more than one person say that the stock yamaha pipes are as good as aftermarket and a lot quieter. It also bugs me that a pipe so similar in design can cost 3-4 times as much as a 2stk silencer from the same company.

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mgorman,
Thumping since 1980
"If the competition is not wasted, the day is"

theMotoMan · Feb 10, 2001

Originally posted by mgorman:
It also bugs me that a pipe so similar in design can cost 3-4 times as much as a 2stk silencer from the same company.

I agree! And how do they justify almost $200 for a header pipe? That has to be easier to manufacture than a two stroke expansion chamber! I think they're milking us.

hardi43 · Feb 11, 2001

Originally posted by PeterEXC520:
Hi Kalitude,

113db? Your TTR must sound like a jet :-)
Here in Germany/Europe the db limits are 98db for moto cross and 94db for enduro. Anke's KTM EXC400 and my KTM EXC520 are about 92db (with the stock pipe). I think my Biggun will be a little bit louder but I hope not too much.
BTW Anke's first race will be in March...
Peter

http://www.gp-racing.de/widowmaker_intro.html

Hallo Peter

was hat dich denn hier her verschlagen?
und wer ist anke?
gruss hardi

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more than twenty year's offroad but it's not enough to finish

PeterEXC520 · Feb 11, 2001

Hi Hardi,

Originally posted by hardi43:
Hallo Peter
was hat dich denn hier her verschlagen?
und wer ist anke?
gruss hardi
[/B]

I'm reading DRN for a while and some hints are very useful ;-)
Anke is my girlfriend.
Peter

Barbuster · Feb 11, 2001

Respond to Dadcrashed,
The stock pipe is not spark arrested and reads 104db on a sound meater. My main concern is 94db not necessarly performance.

longtime · Feb 12, 2001

you might try big gun, they have a quiet, spark-arrested 1 that they say costs no power. you too, kali--why run so loud?

Jonala · Feb 12, 2001

Barbuster,
Try a WR426 muffler. I rode with two guys who had a WR 400 & 426 that still had their stock mufflers. They were both whisper quiet. Neither rider complained about performance loss when I asked about how happy they were with their mufflers.

The WR 400 did have a Thumper Racing insert, it was still quite.

John

toddw1016 · Feb 13, 2001

I ordered the Big Gun quiet series/sa yesterday. Big Gun claims 94-95db at 3500 rmp with increase 2-3 hp over stock in low to mid but loss of about 1.5 up on top.

I currently run a e-series: with 12 disks, at aprox 3500 rmp it is 112-113db, with the quiet insert and 4 disks it is at 103db. But with the quiet insert it runs like I have a cork stuck in the exhaust, and is still too loud. I needed it to pass a 98db sound check at 1/2 throttle for local enduros.

Once I get it I will post my opinion, anyone else running this pipe? Opinions?

Todd
'98 400f

longtime · Feb 13, 2001

hey todd, thx for being responsible enough to spend the $ to get quieter, i wish everyone would do this. i put the big gun on my yz250f, race series w/quiet insert & s.a. the craftsmanship & fit are excellent. it is a good bit quieter than stock, & should pass an enduro sound test, but i haven't really tested it yet. i can't comment on the performance, as it is different enough from stock to need rejetting & i'm not thru with that yet.

ButtonFly · Feb 13, 2001

I just ordered a Vortip for my WR400 having heard another. If you really want quiet, pick up a WR400/426 stock muffler, and stick a Vortip in it. www.finlinesuspension.com holds the license on it, and made a few, these are $59, and Baja Designs licensed the Vortip design (called the baja baffle) and charges $79 for the same thing. www.bajadesigns.com Both are quality products.

PeterEXC520 · Feb 13, 2001

Hi Todd,

Originally posted by toddw1016:
I ordered the Big Gun quiet series/sa yesterday. Big Gun claims 94-95db at 3500 rmp with increase 2-3 hp over stock in low to mid but loss of about 1.5 up on top.
Once I get it I will post my opinion, anyone else running this pipe? Opinions?
Todd
'98 400f

I ordered a Big Gun system for my KTM EXC520 and a separate silencer for closed courses but didn't get it yet. Paul told me that the quiet system will be below 94db without losing any power. The stock system has 92db.
I'll post my opinions here, too.
Peter
http://www.gp-racing.de/widowmaker_intro.html

toddw1016 · Mar 20, 2001

I finally received the big gun exhaust (oversize quiet series with the quiet insert) yesterday, and put it on last night. At idle the db reading at 20" 45 degrees from the exhaust is 84 db. I actually had the bike running in the garage and carried on a conversation with my wife at the same time, that's something new

With the bike at idle I could actually hear sounds from the engine (i.e. valves?, lifters? etc...). At a generous 1/2 throttle it was reading 100 db. The cool thing was it was actually breathing well. I had a white bros e-series and bought their quiet insert. When you put the e-series quiet insert into their exhaust I could notice the engine struggled to rev due to the restricted exhaust flow, not so with the big gun. It is dramatically quieter than the e-series, it has been so long since I had the stock system on that I don't know how it compares to stock, and don't have any db readings from the stock system. I have only ridden it down the driveway and back based on the fact that it was dark when I finished last night. I'll post a ride report after I get the chance to ride it.

Barbuster,
I know you are after 94 db, what rpm distance from exhaust etc.. any particular way you want me to measure it?

'98 yz400f
'99 kk80
'99 ky60
'99 pw50
'98 Lakota 300

simimi · Mar 20, 2001

So if I understand correctly, the muffler from a WR400 will fit the YZ400? and it has a spark arrestor? and it is quieter?

If so, anyone have a WR400 muffler for sale? email me if so!

thanks, mike

simimi · Mar 22, 2001

OK, I have found a WR400 muffler for my YZ400. I need to how I should jet for this set up.

I am currently running the stock head pipe with a FMF IV2 muffler.

Will I need to change Needle, jets, air screw?

I am at sea level in California.

Any help is appreciated as I make the move to Stealth mode......

FastDave · Mar 23, 2001

I'm also looking to quiet down my 1998 YZ400. I had the same idea of putting a WR muffler and saw your posting. Let me know how it works.

Anyone out there have a WR400 muffler they're looking to sell?

Not concerned about performance at this point, just want to ride!!

Barbuster · Apr 2, 2001

toddw1016
todd I need a sound reading 20in. at
45 degrees. RPM I am not sure about. I
have been checking mine at just off idle.
A reading would be great help. If this pipe
is not close I may try a stock wr pipe.
Thanks for the help todd
Barbuster

techman · Apr 8, 2001

Barbuster, get a tach, test at specified rev (about 4000 or 5000) as per MMIC recommendations. Revs really affect your readings. A stock YZ can pull 96 dBA at idle but it's still insanely loud. At spec revs its about 102 to 104 dBA, my guess. Wr pipe is about 96 at those revs.

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YZ 426 too LOUD!!!!!!!

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