Idle high all of the sudden

7 replies to this topic
  • Kyle Prior

Posted February 04, 2007 - 05:01 PM


Hey all, my 426 idle has always been perfect, but all of the sudden, it's really high. How to I lower it again?

  • PumpkinHumper

Posted February 04, 2007 - 05:16 PM


Make sure your pilot jet is clear. Make sure your fuel screw is in place and adjusted correctly.

Then check your valve adjustment.

If that dont do it how long has it been since youve re-ringed it?

  • mxis4me

Posted February 04, 2007 - 05:34 PM


ck your throttle cables for fraying , that could make the throttle hang up

  • grayracer513

Posted February 04, 2007 - 06:27 PM


Also check the spring plate on the back of the slide. With wear, a little chunk of the corner of these will break off and raise the idle. If it's falling apart, you'll want it out of there.

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  • Kyle Prior

Posted February 04, 2007 - 09:29 PM


Alright, I know it isnt the throttle cables or rings, as they are all brand new. Ill check the spring plate when I look at it tomorrow. Thanks for the help.

  • tonto256

Posted February 05, 2007 - 08:14 AM


The hot start plunger may be stuck slightly open. I would check that also. An unaccounted for high idle is usually some type of an air leak.

  • Ztard

Posted February 05, 2007 - 08:50 AM


unplug the tps. just a thought.

  • Leelandc

Posted February 13, 2007 - 03:11 PM


I have a 2001 YZ426F and someitmes when I'm riding, it will be just idling normaly and then all of a sudden it will start idling high for a little while and go back to normal. What would be causing this?

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