Different CDI Units

3 replies to this topic
  • Spadman450

Posted October 04, 2005 - 11:28 AM


I have noticed that the 2003-2005 WR's all have different part numbers for their respective CDI units. I am curious to know what, if any, the differences are.

I have what is basically a 2003 motor and wiring harness with a modified 2005 crankshaft in a SuperKart. The installation of the upgraded crank required changing the rotor and #3 starter one way gear. The motor runs, but we have had gremlins. I was curious if differences in the CDI unit could be causing issues.

Any help would be greatly appreciated. :banghead:

Don E

  • WR_Dave

Posted October 04, 2005 - 02:55 PM


E-mail Mike at MTRacing.com or Richard at Vortex Ignitions and they will be able to tell you if you have a problem. Mike at MT Racing says that the OEM CDI boxes only work for the engine they were designed for. Anyway he can explain it better than I can. Go to the website and give him a call. WR Dave. :banghead:

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  • Spadman450

Posted October 05, 2005 - 05:12 PM


Thanks WR Dave. I called Mike this morning and he was a great help.

Basically, the CDI's for 2003-2005 from Yamaha are essentially the same (they might have some slight differences in the curves). Vortex offers one unit with 10 built in curves to serve all those years and it will interchange with the stock units. Besides the multiple curves (one is stock and models a YZ) the standard unit ups the rev limiter to 11,700 RPM and can be reprogrammed to different settings for an additional charge.


Don E

  • WR_Dave

Posted October 05, 2005 - 05:20 PM


No problem with the help. I just installed mine today and all my problems are now gone, except for the bike runs really strong and picks up the RPM's very quickly resulting in some great wheelies. You won't be disappointed, Good Luck--WR Dave. :banghead:


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