Wr426 correct jetting

1 reply to this topic
  • xBl4cKH4wKz

Posted February 16, 2013 - 05:53 AM


Recently i have bought a wr426 that has been raced before... However it just had its top end rebuilt and as far as im aware it only has a titanium straight through akrapovic exhaust.. However i think that the jetting jn the carb is wrong as when doing about 2,000 rpm the engine chockes a little as if its misfiring but its chucking too much fuel.. Can someone tell me whats the correct jetting for a stock wr426 and for one that has an acrapovic exhaust on it? Thanks

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  • Thommo_400f

Posted February 18, 2013 - 12:59 PM


Once you mess with the stock setup there is no "Correct Jetting", only what is right for your setup, waaay too many variables in each persons setup.
A good starting place is to look in the manual.
You should pull out your Carb (you are going to have to anyway to make any changes) and list your current jetting for us to see and I'm sure it would be sorted pretty quick.
Make sure your air filter is CLEAN.
If you are getting a low to mid throttle sputter then it is most likely rich on your needle.(See attached diagram)
A good start is to move the clip to a higher notch (closer to the top) which will lean it out slightly.
You should notice the sputter get less and possibly move to a higher rpm range.
If you get all the way to the top clip position and there is still a sputter, you may need a larger diameter needle.
I suggest this method first as it is a good test and FREE (unless you need to buy a new needle)

Like I said.....List your jetting

Attached Thumbnails

  • CarbAdj.png


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