fmf factory 4 for 04' wr450

I just ordered my new factory 4 exhaust system for my bike and i was wondering how it performs,and has anyone else done this with there bike.I cant wait to put it on.

no one has done this?

I can only tell you that a stock YZF450 pipe and air box mod really woke up my bike.

The difference from the pipe and airbox mods was like going from a strong 125 2stroke to a 250 2 stroke.

Make sure you open up the airbox so she breathes better on both ends to get the full effect.

Oh yeah depending on your elevation and temps youll have to richen every circuit.

The pipe and air box made way more difference than the cam did. And the next best mod for power accelleration and response would be a 52 tooth rear sproket. :)

jc777 Did you get your pipe Yet? How load is it? How much weight did it take off? I am trying to decide which pipe to get. :)

nah it hasnt come in yet , but it should be here in the next couple of days ill post when it gets in.

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