Noisy Yamaha's

Failed a sound test at 105 db's in April, with the White bros. pro meg and high boy pipe. Removed all but four disc's and installed a quiet core, passed at 96. Decided to jump on the jetting band wagon and back up to 101. Bought a Fmf Q and power bomb, still sounds as loud as before. I bought the bike with the WB exhaust, now looking for a stock silencer :mad:Whats up with these bikes, why are they so loud compared other makes? :)

My 99 YZ400 produced 104db with the WBros pipe on it. Took out must of the disks and it only dropped to 102db.

It is my understanding that due to the engine design of the Yamahas, they are the loudest of the pack. The new 450's are quieter, so I hear ( :) ).

Call FMF. They should know how to meet 96db on that bike.

I have a WB r4 got it from 107db down to 98.7db

I am working on a couple of things to get it down further So Stay tuned for that but

Try using a combo of stainless steel whool as the first layer and then one wrap of fmf 4 stroke or high density packing. This will or should drop it further

Pro Circuit has the new 496 talk to Blue he has a new one. White Brother has a new E2 coing out in Oct that meets 96db,, Bug GUn has a new Set due out that is 94 they claim. FMF Sucks

It is my understanding that due to the engine design of the Yamahas, they are the loudest of the pack.

I wonder why they would be the loudest. Im thinking it is because of the extra valve, any thoughts.

High compression, high horsepower, high noise. The quality of FMF is terrible. I hope White Brothers new pipe is quiet, but I'm tired of throwing C-notes at the noise. I'll go back to stock if need be. :)

why does fmf suck im thinking of buying hte powerbomb header and 17inch can with the anodized finish... is it just the quality of the pipe that sucks or is it the performance gains :)

Quality compared to other brands. Look at the construction and weld quality of WB or PC. FMF must be re-packed every 20 hours for them to honor the warranty when the silencer burns off the pipe. But I needed something quiet and got tired of waiting for the PC 496 that I ordered... :)

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