07 WR450 Jetting?

4 replies to this topic
  • Race Face

Posted October 27, 2009 - 03:10 PM


My 07 WR450 is about 2yrs old. I've done all the mods minus the air box and air injection kit. I just installed a White Bros header and pipe. Doesn't seem to be running as well at high rpm. I've checked White Bros website, couldn't find any info on jetting. Do I need to change the jetting after installing exhaust? Is the air injection causing this? Does anyone have a preference for jetting. I ride in southern California deserts, anything would help.


  • William1

Posted October 27, 2009 - 03:59 PM


When you install a more open exhaust, you need to richen the jetting. There is not single jetting setup for a particular bike model or exhaust. You must test your bike and adjust to suit for your bike and where you ride. But I suggest trying a main at least 2 sizes larger and possibly raising the needle a clip or two (movng it farther from the top/flat).

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  • KennyMc

Posted October 27, 2009 - 04:00 PM


Check out this for jetting suggestions. I run the JDJetting kit with the 168 main and 48 pilot.


  • tribalbc

Posted October 27, 2009 - 04:11 PM


I would suggest opening up that airbox as well.

  • Race Face

Posted October 27, 2009 - 04:19 PM


Great! Thanks guys.


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