Frame swap, now no won't idle, running lean

3 replies to this topic
  • 67baja

Posted March 06, 2011 - 03:57 PM


I just performed a frame swap on my 08 wr450. Now that I have it back together, the bike will idle with the choke on (very high idle), but as soon as I turn off the idle if the thottle isn't opened up quite a bit, it just dies. And this bike pops like mad when engine is decelerating. I pulled the pilot jet and it is clear. Are there any vent hoses or electrical connections that will cause this?

Any ideas what to check next?

FYI - this is the most UN-user friendly bike ever to work on.

Edited by 67baja, March 06, 2011 - 11:02 PM.

  • ronbuell

Posted March 06, 2011 - 04:02 PM


Not enough info. You don't say what you swapped and what you used from the old bike. Sounds like a fuel issue, like dirt in a used tank got to your carb and blocked up the main jet and accelerator pump. Or you used a different carb that had different settings from the original..... More info needed on what you did.

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  • _Hitman47

Posted March 06, 2011 - 10:34 PM


If all the intake components are the same, my bet is on vacuum leak.

  • 67baja

Posted March 06, 2011 - 11:01 PM


The guy I bought my bike (an '07 wr450) from financed it and never paid it off so I can't get the title for the original frame. A guy in my race club parted out his bike (an '08 wr450) so I bought his frame (with title). The only thing I changed was the frame. I re-used every hose, wire, nut, bolt, suspension, radiators, seat, tank, sub-frame, air box, plastics, etc from my '07. This is a big job to do with as many freaking hoses and wires this bike has, which leaves lots of places I could have overlooked something.

Vacuum leaks sound likely. I'll check for that next.


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