2005 kx125 jetting

5 replies to this topic
  • motorgeek32

Posted April 09, 2010 - 04:28 PM


[COLOR="Red"]hey guys ii have a 2005 kx125 and wants to know the stock jetting because im fouling plugs alot and thats what one of the mechanics said the main jet now is 460 i know which is too big but people are saying that 260 is a good jet size. all of my other jets are fine, :thumbsup: and i have full fmf systme, big bore kit (144). i clean my airfilter every 3 to 4 rides and clean my carb every month . my friend says its the jets and i think its the main jet so can someone help me?:worthy[/COLOR]:

  • crider400

Posted April 09, 2010 - 04:58 PM


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Posted April 09, 2010 - 08:11 PM


Wow, 460 main jet?????? That freekin huge. You need to take that down to atleast a 400.

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  • motorgeek32

Posted April 10, 2010 - 06:41 AM


kk thanks guys

  • 07gixxer600

Posted April 11, 2010 - 04:42 PM


Ya, 460 is huge... Im wondering if your mechanic is wrong, or someone had no idea how to jet when they did it... 420 is the stock main jet in that bike.

With the 144 kit a 200 might be too lean, goto 420 first just to make sure. All depends where you are but my 04 kx 125 with a 133kit I want to say had a 410 main jet and was perfect.

Too lean is bad, so if you dont know exactly what your doing take it slow.

  • motorgeek32

Posted April 11, 2010 - 06:37 PM


hey, ya just put a 370 main jet and it works fine

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