Carb issue

5 replies to this topic
  • enkd1004

Posted January 31, 2011 - 08:01 PM


Hey guys,

OK so here is my problem. This last weekend I successfully installed a new JD jet kit in my 02 WR426, #170 clipped 3rd from top installed a new NO-Toil air filter, changed the radiator coolant and replaced a bad in-line fuel filter. The bike starts a whole lot better than it did previously since it was jetted for higher altitude. The bike idles fine until I give it a little throttle then the rpms go really high and at times will even continue to go up until I hit the kill button. Today I thought I would tinker with it a bit and see what I can come up with. I start the bike and mess with the throttle knob and got it to idle ok then gave it a little gas with the same result, I then decided to put it in gear and rode it down the street I then realized that when I let the clutch out the rpms go back to a normal idling level. No problems while I was riding it at all, any thoughts?

Thanks in advance

  • wrwest

Posted January 31, 2011 - 08:24 PM


Bottom end is 2 lean . Open the fuel screw on the botoom of the carb 1 turn and see what happens.

  • enkd1004

Posted January 31, 2011 - 08:28 PM


Bottom end is 2 lean . Open the fuel screw on the botoom of the carb 1 turn and see what happens.

The jet kit instructions said 1 1/4 turns so thats what its set at. I will try it at 1. Do you think it could be the accelerator pump?

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  • _Hitman47

Posted February 01, 2011 - 01:10 AM


What wrwest says is to open it up 1 turns more, so try it at 2 turns. My bet would also be around 2 turns. You're too lean at the bottom end and idle setting is too high. If you jet the bike correctly you'll get consistent high-rpm idle. then turn idle setting to normal rpms.

Best pilot jetting procedure for me was following:

On warm bike, I repeat, fully warm bike, hold your clutch in and open throttle by smallest amount you can and listen to revs. If bike responds immediately, then it is not lean, but if revs remain constant and then, after some time jump up, it's sure indication of lean running bike. This effect is more evident when you apply smaller throttle, I'd say less than 1mm. Open up pilot screw by small increments, 1/8 of a turn until bike start to respond to any minute throttle change immediately. Thats all.

  • dgcars

Posted February 01, 2011 - 01:33 AM


If you are still having an issue after this, check for air leaks on the inlet side

  • yz-dwg

Posted February 02, 2011 - 11:07 AM


maybe look at your cables??


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