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.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • 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.


Related Content


Is the 2016 GYTR Yamaha YZ450F too fast? by Fryboy

Dirt Bike   Special Interest Forums   Pro Racing
  • * - - - -
  • Hot  241 replies

Thinking about Yamaha 250... by Arctic Pride

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  491 replies

Need help by Goforaride

Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  68 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.