Fixing a bent/creased header pipe

On many of todays new 4 strokes the head pipe is very expensive ($150-$250) and they bend rather easy if you fall or wreck on the right side. Since the big manuacturers of exhaust/head pipes "hose" us on the price (like: FMF, White Brothers, Noleen, Pro Circuit, DSP, Yoshimura, GYTR, etc) it makes since to repair the header you have instead of buying a new one, right? Well I am going to tell you the procedure to fixing your bent header!


1/4" thick steel plate (4" x 12") $6.97
Galvanized bolts/nuts/washers $ .69
1 1/2" Rubber expansion (freeze) plug $3.22
7/16 drill and tap $8.55
air chuck male connector $ .99
old tire tube (to seal it better)
safety wire (to hold the plug in)
Total- $20.42


  1. You need to take the header off the bike.
  2. Then plug the tail end with a 1 1/2" rubber expansion (freeze) plug. Then for safety I wrapped wire around the screw and left about 2 inches off of each side of it and draped it down the pipe. We took a clamp and tightened it over the wire in case the plug came loose it would be restrained by the wire which is held by the clamp (it did come off one time so never get in the path of the plug).
  3. Then we took a flat piece steel plate which was 1/4" thick and 4" wide X 12" long and drilled two holes to match the header flange. In the center of these two holes we drilled and tapped a new hole to fit a standard air chuck. This is so that you can bolt the header flush to the metal plate.
  4. Thread the Air chuck into the center hole (make sure you use teflon tape around the air chuck, so that it seals better).
  5. Now you must attach the header to your "jig". I used a old tire tube inbetween the header and the steel plate so it would seal better!
  6. Now attach the air hose to the chuck. (If you have a regulator set it at about 80psi) heat the dent or crease evenly till it is red hot and it should slowly start to come out (propane does not burn hot enough to get the crease out you must use o2/acetylene). Make sure you keep the torch in constant motion and do not heat one area too much (or you risk blowing a hole in your header)!. As soon as it starts to "pop" out make sure you watch it...and when it gets close to being to the original, release the air and stop heating. We released the air every 2-3 minutes in case O2 has gotten into the pipe.........very dangerous, have a hammer nearby in case the pipe swells too much you can tap it back while it is still hot. cool it down and wire brush it. You will be the only one that notices!

    I think $20 to repair your pipe is a bargain. And I'm sure you will use this many times, for yourself and friends/etc! I just thought I would let you guys know this, because I was excited whenever my header was fixed!

    This jig was made for a YZ426, but it can be easily modified to work on KTM, DRZ, KLX, TTR, XR, CRF, and even two stroke pipes! All you have to do to make this jig for another bike is drill the holes in the place where your header hooks up to!