2001 YZ426F Jetting question... Please help me

2 replies to this topic
  • inocent_sinner

Posted December 04, 2009 - 04:55 PM


I just put a Big Gun EVO limited edition (not sure if that makes a difference or not) exhaust and header on my YZ426F. And I can't find any where on the net about what size jets to run... So can anyone help me out on how to setup my carb for this type of exhaust. I live in Arizona and will attend the dunes at times (Glamis and Gordons Well). I need to know what size to put in the... main jet, pilot jet, and where to move the clip on the needle, and how many turns do I need to turn the air screw... Thanks in advance for all your help

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  • grayracer513

Posted December 04, 2009 - 06:49 PM


What's wrong with the jetting it has in it?

Most of the time, major rejetting is not required when installing aftermarket exhausts, and it's just as likely to need to have leaner settings as richer.

Check the jetting sticky at the top of this forum index, and look at these two, from the Common Threads sticky:



  • inocent_sinner

Posted December 04, 2009 - 09:16 PM


I am not sure what is wrong with the jetting that is iin there, if theres a problem or not. I did notice that the header gets red really quick mabye less than a minute. I know these don't have fans and no air circulation will casue them to get red. But I also read that this could be an issue with jetting? So that is why I posted this thread. I wasn't really sure on what size jetts to put in and where to set the slide needle. Thanks for pointing me in the direction to figure out if I need to change out the jets.

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