WR426 no spark...need advice!

4 replies to this topic
  • e36graduate

Posted August 29, 2012 - 02:24 PM


Just rebuilt my tranny after snapping a chain and bending a bunch of parts in the tranny. Put everything back together and now I can't get the bike to start?

If I take the plug out and ground it and kick over the bike with the decompressor, I get NO spark.

I checked the coil resistance and resistance of the pick up coil and it was in spec. I can't get a resistance reading on the primary and secondary coils through the CDI...not sure what thats about. I can't get a reading on the primary or secondary coils when I tie into the wires down by the stator.

Is there a way to check if I am getting any power directly from the stator when I kick over the bike? If so, how would I do this and how much volts (DC or AC) should I see when the stator/magneto turn?

I have a YZ426 stator that I checked and the pick up coil (red/white wire) is in spec and I can't get a reading on the primary/secondary coils (brown/blue/pink).

Before I buy another CDI, was trying to see if I could tell if the stator is good or not...it worked okay before i rebuilt the motor?

  • dustdogg

Posted August 29, 2012 - 02:49 PM


Did you replace the plug and try it? When my 426 did this last year I pulled the plug, grounded it and kicked it over a few times. The spark was very week so I figured I would put a new plug in and go from there. It started on the first kick and have had no problems since. Not sure why it did that, because the plug "looked" fine but I guess its just one of those things. Plugs are cheap and easy so I would start there and if thats not in continue testing.

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  • GCannon

Posted August 29, 2012 - 02:53 PM


Did you paint the Frame? if so did the Secondary coil recive a good ground? did the motor and Stator get a good ground as well?

Edited by GCannon, August 29, 2012 - 02:54 PM.

  • e36graduate

Posted August 30, 2012 - 01:32 PM


tried a few plugs...no spark. did paint the frame, but that was before the bike died. Really would like to know how to measure voltage coming from stator......!!!!

Also, what wires coming from the stator are actually needed to make the bike start and run...not worried about lights.

What does the pick up coil do? The little do dad that sits on the side of the flywheel and has a red/white wire coming out of it.

  • waterkid

Posted October 08, 2012 - 05:17 PM


Did you find any conclusions? I have a WR400 with same problem. One day it worked next day I got one burp and now nothing.(ussually fires up in 1-2 kicks) Replaced the pick-up coil because its way cheaper than a cdi (it must have gold in there somewhere). Have to go to electrix to get that as the dealer wants to only sell you the whole stator and assembly.

Trying to find a used CDI, anyone have one ? If I spend another 300bucks and it doesn't fix it, hard to explain to the wife.



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