Hey guys,

I was told this weekend that I need to change my CDI curve for the WR with YZ timing? Is this true????


I don't know if you have too. The WR may have a little tamer ignition curve to help with wheelspin but I don't know for sure, maybe they are the same? Do they have different part numbers?


The proceeding nonsense brought to you by MotoGreg

On two wheels (or 3) since 1970

'92 GSXR 7/11 (Until I get a shwangy 916)

'99 WR/YZ400F 'Cause thumpers rule and two strokes drool!

Visit my photo album for the bargain price of $75 - ENTER AT YOUR OWN RISK - EVIL LURKS WITHIN!

Greg, I know who is our Part Number expert.

Matt from NZ, come on down!

98 WR400 2YG-85540-M0-00

99 WR400 5BF-85540-00-00

00 WR400 5GS-85540-50-00

98-99 YZ400 5GR-85540-00-00

00 YZ 426 5JG-85540-00-00

I found these P/Ns at the following link:

YZ & WRs CDI units have different P/Ns. I don't know how to find out what the specific changes are in the curves. Although I currently don't have one, I would recommend an after market CDI with rider selectable curves like the Vortex before I would plunk down the $200+ on a YZ CDI.


we thrashed this one out about 2/3 months back mitch, try looking up "vortex". clarke has it on the bike & after one of the curves wasn't quite right he's got it going really well.

i would suggest you go back & look at it though. i think it was agreed that the wr ignition works at low revs but deliberately retards near top revs to stop wr owners revving them out.

the mags say that yamaha have altered the ignition for the 2000 bike but i believe that that was to stop them stalling & that's all.

Matt porritt sells them.


ps there you go Mitch!!

[This message has been edited by Taffy (edited 09-18-2000).]

[This message has been edited by Taffy (edited 09-18-2000).]

I had a little time on my hands and switched the YZ box , off a friends YZ, and put it on my WR. I could not tell the difference between the two personally. I don't think the yz rev limit is any higher than the WR. I may be wrong about that, but it definetely is not worth the money. I'll go with the vortex box.

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