01 YZ 426 Tuning help

1 reply to this topic
  • MotoMatt

Posted August 03, 2009 - 03:41 PM


I am at 5300ft of elevation.
I cannot seem to get the jetting correct. I have the white bros R-4 slip-on and everything other than that is stock. I did the BK mod but it seems my jetting is soo far off I cannot tune it. It pops and back-fires, does not idle and is really making me wish it was fuel injected.:thumbsup:
It seems to run ok with the choke knob pulled out. As soon as it is pushed it back to poping.
Any help would be greatly appriciated

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  • 642MX

Posted August 03, 2009 - 04:13 PM


Check for a restricted pilot jet or pilot circuit.

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