Engine Problem

4 replies to this topic
  • Ranger426

Posted June 20, 2011 - 04:27 AM


I have a 2001 YZ426F and it has been running perfectly. Yesterday I went trail riding and rode all day, bike ran fine. Later yesterday evening we went for one last run and we had cut off on the road and while I was just cruising down the road it started missing like it was running out of gas. When I pulled off it was idling fine. So I just limped it home and noticed the header was glowing orange mostly at the head but when It needed more throttle to pull a hill the glow would move farther out the header. I'm unsure of what the problem is and just hoping and praying its nothing too serious. Anybody have any insight on the problem.


  • dgcars

Posted June 20, 2011 - 04:57 AM


Headers glow brighter as it gets darker. Could be a multitude of things from electrical to dirt in the carb.

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  • baxterj787

Posted June 20, 2011 - 05:17 PM


1) PLEASE read FAQ section on "The Fabulous Glowing Red Header". Lots of other good info in the FAQ section, too.

2) The surging / miss you described might point to a throttle position sensor (TPS) on it's way out. They usually cause an odd running condition at steady state part throttle.

  • Ranger426

Posted June 21, 2011 - 03:34 AM


Ok I'll look into that. Thanks for the help.

  • Ranger426

Posted July 17, 2011 - 09:42 AM


Figured it out....the CDI went out. Bought one and put it on, the bike runs good as ever.

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