02 426.....???

5 replies to this topic
  • ross engineering

Posted September 09, 2008 - 12:18 PM


I picked up a nice 02 wr 426 the other day. Hasnt been run in over a year, gas was still in the tank, carb was filled with jelly......cleaned all that up nicely, pulled plug and laid it on the crankcase, kicked it over, got good fire.....but cant get it to even try to fire and stay runnin......i"ve double checked my carb cleaning job twice and still no results.......:thumbsup: any suggestions?


  • grayracer513

Posted September 09, 2008 - 12:46 PM


Quite frequently, the pilot jet will plug up under circumstances such as you describe. If you do not remove the jet and clean out not only the fuel orifice, but any cross holes you find, you'll leave enough contamination in place to cause a problem. A set of wire drills ("number" drills, #61-80) are helpful. Use the largest drill you can push though the jet by hand without spinning or twisting it. You want to remove the varnish, not change the size, even a little.

Also critical are the air jets in the face of the carb, and the starter jet. Correct setting of the idle mixture is also a biggie for these engines, although it's more important for hot starting than cold.

Most, if not all, new owners of YZF/WRF's run afoul of the starting procedure, also. It's known semi-affectionately as "the drill". 426's are very fussy about having it done right:



  • WR_Dave

Posted September 09, 2008 - 01:14 PM


Also when you have the carb apart make sure to remove the float needle seat and clean the screen on that as well. WR Dave :thumbsup:

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  • byggd

Posted September 09, 2008 - 03:47 PM


Sometimes when cleaning the jets you just “think” you get them clean. Happened on my wife’s bike once. Be sure you cleared them completely.

  • ross engineering

Posted September 10, 2008 - 02:46 AM


cool. Thanks guys. picking up a couple of new plugs and gonna hit her hard again tonight....Let you know what I come up with.

  • matt4x4

Posted September 10, 2008 - 03:58 AM


Couple of things to add since you're new to the bike:

DO NOT remove the TPS
Make sure you remove and clean both diaphrams and associated components, check all carb vent lines are clear and know how to properly start the thing - many people kick for days because they don't know "the drill". Very important to know "the Drill"


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