Exhaust time

I have had my 2005 450 for about 2 months now and love riding it, especially after the free mods and tuning it. Here is what I have done to it.

Throttle stop, grey wire, air box mods, AIS removal, JD jet kit, Zip Ty fuel screw. Next on my list is exhaust.

I think I have narrowed it down to the White Brothers W2 slip on. It's affordable and I think it looks real nice. My question is who is running this exhaust? does it sound good? is it real loud? I want to get a quiet insert for it for trail riding to be quiet but be able to open it up if I go to the dunes. I want something deeper than the stock one, not necessarily louder just something beefier since it sounds like its been neutered.

Thank you in advance :banghead:

Anyone know about the jardine rt4 dont hear much about it but I have heard its good on the YZ.

Since you cant run a loud pipe in the dunes 96db max, you shouldnt even think about buying anything other than an FMF Q2 or TiQ w/ a powerbomb header. That will be about 94-95 db. And still runs strong!

The only other system that will let you WR run well is the CRD systems.

Everything else is just loud, Sure they have inserts that make your bike run like crap. Dont waste your $ on them.

Yamaha four stroke motors are harder to quiet down because of the 5 valves.

If you get a PB header order the heatshield.



Yamaha four stroke motors are harder to quiet down because of the three exhaust valves.

I've heard everything now!

Holy crap, I must have my carby on the wrong side of the motor. No wonder I keep going backwards.

Yamaha four stroke motors are harder to quiet down because of the three exhaust valves. Eric

It's three intake valves and two exhaust valves :banghead:

If Ya all just heard a loud popping sound, That was my head exiting my ass :banghead:

My point was Yamaha 4 stroke motors make more noise than others Period.

I tried a PC 496 Didnt pass the sound test. 101db "96db my ass"

Tried a Q by itself, to loud 99db

FMF gave me a free Powerbomb header and finally my WR ccould pass a sound test barely. I now have a Q2 w/PB header and this combo is about 93-94 db.

Sorry for the typo, I know better and expect to be corrected if wrong.



How does it make more noise?

If Ya all just heard a loud popping sound, That was my head exiting my ass
Dude, that is friggen classic. I am gonna have to use that one. :banghead: As far as the earlier question about the WB E2, its ok. Running it with the quiet cap in robs lots of power. Without the quiet cap, well, its not quiet...very loud. Sounds like the FMF system may work better for you.
How does it make more noise?

Higher compresion and the 5 valve motor had FMF scratching there heads as to how to really make Yamahas quieter.

Put an old Q on a CRF or DRZ and they passed a 96db test.

Put the same on a YZF and it would fail.


Thanks for the help guys, is the FMF 4.1 the one I should look into or is there something better from them?

The Yamaha is known as being harder to muffle than brand X. The FMF 4.1 is closed course motorcross exhaust. Probably the only aftermarket exhaust that will work for what you need will be the FMF Power Bomb header and either the Q or Q2 muffler. I don't know much about the exhaust from CRD but it might work well too. The motorcross type exhausts are very loud and if they do manage to pass a sound test with an insert they will make less horsepower than a FMF Q. Without the insert they will definitely perform better but it is usually a small accepted sacrifice for most people. I am not sure if you have the skills or the means but modifying the stock exhaust can make a considerable power improvement. By removing/modifying the baffles inside your stock muffler and adding a larger outlet tube (either homemade or one from Pro Moto Billet) you can make a great performing muffler. If you use the PMB outlet you can also put back your stock outlet when the bike needs to be quieter. I modified my girlfriends exhaust on her 250 and I am stunned by the power difference. It is now a great sounding exhaust and it is pretty close to the sound output the FMF Q on my 426. I think the mods are well worth the time with the exhaust prices these days. You can spend the money saved on some other cool goodies. Here is a link to the 250f thread that I posted about this mod a while back. http://www.thumpertalk.com/forum/showthread.php?t=282449&highlight=muffler . If you have any questions about this mod feel free to ask or PM me.


I could alter the stock muffler but I would rather bolt on a new and make more power and lose more weight.

Found a pretty good buy on the Q2 titanium slip on so I think I am gonna give that one a try. I think I will be able to get this and then in a month or two add the power bomb header to it? I don't see any reason why thi wont work.

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