What head pipes fit a 426?

Hello, i looking for a head pipe for my 426, im going to hack it up anyways but just wondering what will "bolt on" or fit? I hears the 400 fit (i can see that) but i heard that some 450 pipes fit too. Just need some confirmation.

Thanks!

~Shawn @ BMS

I think I know what bike this is for...

The 400, 426, and 450 all have the same diameter outlet at the head. I believe the stud spacing at the exhaust port is the same also, so if you are going to cut it up I believe any of them should work as far as mounting. If you want to double check, call FMF and ask if the mounting flange for a YZ400F is the same as the YZ426F and YZ450F (since FMF uses a separate flange from the rest of the pipe).

Good idea^ I thought they were the some bolt spacing and diameter too. Ill give them a call.

~Shawn @ BMS

I have several exhausts and head pipes (oem, jemco, fmf, jardine, ect.) that all fit between a 99 yz400f, 01 yz426f, 03 yz450f, and my '06yz450f. 98-06 you should be set.

I have several exhausts and head pipes (oem, jemco, fmf, jardine, ect.) that all fit between a 99 yz400f, 01 yz426f, 03 yz450f, and my '06yz450f. 98-06 you should be set.

Good to know. You can add 07-09 to that list also, as they are the same diameter at the head and have the same stud spacing as all of the other 450's, but they are bigger at the midpipe joint than the 03-06.

So if the head pipes fit, does the rest?

So if the head pipes fit, does the rest?

No. The bends are different between all the head pipes, the diameters at the midpipe are different between pipes, and the mounting points and bends in the midpipe are different. All of these headpipes are not interchangeable, they will all just bolt to a 426 head. He is going to cut and weld, so bends and diameters after the head don't matter to him.

^Thanks, thats what i needed to know. Im trying to stay away from the OEM Ti pipes, anyone know what years they were on the bikes?

~Shawn

The headers were titanium from at least 2001 onward. None of them were ever steel, but the YFZ quads and WR' were stainless, as are a number of aftermarket pipes. The WR's were a smaller diameter tube beyond the port, however.

Thats good information.^

~Shawn @ BMS

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