How do you tell if the CDI is BAD?

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  • MountainManic

Posted May 01, 2007 - 12:59 PM


I have an 02 YZ426F that I have been converting to a supermoto bike. I recently installed the WR stator and flywheel with the YZ pink wire mod and the bike ran fine. I then went home and began finallizing all my street legal wiring part of which was wiring in the stator to the 12volt power supply by connecting the stator to the regulator recitifer. When I tried starting in I quickly discovered I had lost spark.

So I am by no means an electrician, but I have been banging my head for a week know and need help. By playing around with the manual as well as my voltage meter I get spark from the stator to the CDI via the green and brown wires. By looking at the diagram it looks like the spark excites the CDI via the orange and black wires to then attatch to the iginition, however when I test it for spark its not there.

I dumped too much money into it thus far to just go buy a new one and I am too inexperienced to make this decision about its validitiy to say yes or no. The yamaha manual blows saying to test everything before then and if it all works its busted. Does anyone have any light to shed on this?

The only thing I can think is that i may have fried it when I was wiring and the 12volt battery wire from the postive terminal touched the frame and lit up the system and I thought wierd but quickly moved it off and taped it. DO they fry that easily? Thanks for any advice.

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