YZ426 carburetor question

2 replies to this topic
  • yz450scott

Posted June 15, 2010 - 08:05 PM


how do I adjust the screw with the spring above the accelerator pump rod just below the throttle cable connections at the carb. I am not sure what is does and my manual if very vague..:thumbsup:

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  • Dudemeister

Posted June 17, 2010 - 05:37 AM


Do you mean the one which is directed to the other side of the carb and has a black knob? That's the idle adjust (it raises/lowers the throttle valve).

  • grayracer513

Posted June 17, 2010 - 07:56 AM


That screw is for the adjustment of accelerator pump timing. The '01 manual doesn't cover it at all, really. Download an '03 manual here:


Look at the procedure on page 4-19 and use that as a guide. Then review this thread:


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