want 2 know a good after market exhaust 4 04 450 :thumbsup:

what sort of performance are you looking for. top end or bottom

stock YZ muffler with GYT-R header pipe works well on the 426 and can be had for a good price too. Cant see the 450 being much different.

Billet makes a silencer insert.

I rode stock baffle-less for a while and liked the boost but the po po didn't like it too much, plus I run it on the street. I can't complaine one bit about the billet insert, two second install and I was good to go.


I have the standard exhaust and took the butt-plug out for doing a bit of offroading. I fired it up in london, dogs starting howling, curtains opened and little girls stuck their fingers in their ears and scowled at me. Gonna get a pro moto billet insert.

Cant go wrong by the FMF Powercore IV, louder than stock but with a very healthy performance gain, they even have a quiet core insert for when you need to be less noiser.

It all depends on the amount of money your willing to spend. I bought a used factory YZ muffler ( Off ThumperTalk)and it made a big difference, alot quiker throttle response.

I agree with everyone else, it depends on how much money you want to spend and the type of performance you want.

I wanted to get reasonable gains from the free mods and to try to stay within the Michigan 94 db limit, so I bought the GYT-R insert. Installs in minutes, looks OK, not sure about the sound level. As for performance, the mods in my signature have made it faster than my skill level.

Good enough for me!

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