02 YZ 426 Red Hot Header

6 replies to this topic
  • Jetted

Posted January 12, 2009 - 06:28 PM


Hello all. I'm new to the TT forums, however, I am not a virgin forum user. I have tried to look my problem up using the search feature but it doesn't seam to be working. Anyways back to my issue.

I have a 2002 YZ 426 that I just finished referbishing. Upon starting the bike after the rebuild I have noticed that the header gets red hot. It is important to note that I replaced both cams with the stage 1 Hot Cams and installed a complely new exhaust from FMF, Power Bomb Header and Power Core 4 silencer. Does anyone have any ideas of what may be causing the header to get so hot? Thanks in advance for your help.

  • xl-one

Posted January 12, 2009 - 06:58 PM


You're going to get yelled at! All of us noobs ask that same question...the answer is that it's normal...there are several threads on this! (actually, you won't get yelled at, everyone here is ultra cool!)

  • Jetted

Posted January 12, 2009 - 07:03 PM


I figured this has come up before. For some reason when I click the search button the window doesn't drop down right away. When it does and I move my cursor to the window it disappears. Go figure.

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  • mxboy12346

Posted January 12, 2009 - 08:33 PM


yes it is normal considering it is a four stroke.But after installing a new exhaust you 95 percent of the time have to rejet.

  • 642MX

Posted January 13, 2009 - 10:06 AM


Its normal, they all do it. It will also blow coolant out if you let it idle long enough.

  • jrny426

Posted January 13, 2009 - 10:43 AM



  • Florida_426

Posted January 14, 2009 - 09:54 AM


The cherry red glow of the exhaust header is just the nature of the beast with a 4 stroke bike. Extreme temps are reached in the exhaust header. As long as your plug reads good you are safe.


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