03 YZ450 stock pipe, will it fit on a 03 WR450?

[Vick115]

Has anyone tried a stock 03 YZ450 pipe on a 03 WR450?

[yamaboy233]

Yes it will fit. But you will need a longer bolt for the silencer mount near the rear fender. The stock YZ450 bolt wont work because it is to short. The YZ450 subframe is different than the WR's. But I bought the washer that goes on the back of the rubber piece that goes aganist the subframe. So all you need is a longer bolt and your good to go. And the head pipe is the same as the wr's. I have this setup on both of my 03 and 04 WR450's.

[Vick115]

IS there a difference in power? i have been told that the stocker off a YZ makes a big difference in performance.

my checkbook is a little short or i would just do an aftermarket pipe.

[yamaboy233]

The only thing I can tell is that it makes it strong all through. And that it is a little more pepper of the bottom. I dont think that I would buy an aftermarket exhaust. I bought one for my 03 WR450 and didnt like it as well as I did the stock pipe. All the aftermarket pipe did was make it louder. It wasent to much louder than the stock yz, but I felt that for the GNCC's which is what I race, the stock worked very well. And you can pick up a stock complete system for a $100 dollars or so off ebay.

[Vick115]

thanks for the reply, im gonna start looking for one to try.

[KentuckyWR]

The only thing I can tell is that it makes it strong all through. And that it is a little more pepper of the bottom. I dont think that I would buy an aftermarket exhaust. I bought one for my 03 WR450 and didnt like it as well as I did the stock pipe. All the aftermarket pipe did was make it louder. It wasent to much louder than the stock yz, but I felt that for the GNCC's which is what I race, the stock worked very well. And you can pick up a stock complete system for a $100 dollars or so off ebay.

You gonna be @ Loretta's???

[yamaboy233]

Yes. I was 3rd place. Open C. 37th out of 435 riders Overall

Did you go?

[WR372]

whats the db of a stock yz pipe? Do they need anything like spark arrester, insert?

[yamaboy233]

At the big buck GNCC they did a sound test. And it was 100db.

[MountainMax]

is there any jetting needed to be changed if you just change the muffler??

[BEAN329]

I put a 05 YZ on my 03 WR and after changing the idle jet and the main jet, boy what a difference. I love it. I have a FMF powerbomb SS header by the way. The other thing I noticed is the rear shock reservoir gets very close to the mid section of the exhaust pipe. I placed some rubber on the frame so the reservoir does not come into contact with the exhaust. The mounting bracket should be no problem. Good Luck

[MountainMax]

how much did you jet it up? was the muffler the only change you made when you rejetted? im jetted now as per the sticky thread here with all the free type mods done. Also, did you put on the header by itself or at the same time as the muffler?

and which header did you buy, I see they make 4 different ones for my 06 WR450