a timing change?

Can I use a WR450 09 CDI box on my 08 YZF450 for the timing change?

No. The WR box runs off of DC current, the YZ uses AC. The electrical systems are completely different.


What do you want out of the timing change?  There are alternative choices within the YZ450 line.

I want the  tractor like power of the WR 450. Also I have bought the heaver flywheel to help out, What next?

Rekluse, Steel Clutch basket, 18" tire, steel sprocket, Bibs, gearing.... all things to do before swapping CDI's. never heard of a 450 not being a "tractor" in stock form but too each their own.

I want the  tractor like power of the WR 450. Also I have bought the heaver flywheel to help out, What next?


Then what you probably really want is a set of cams from an '04 WR450, along with the CDI from an '03/4 or '06 YZ.  You'll loose some top end, and you can't put as heavy a flywheel as the WR carries on you engine without some expensive changes.


Try this first:  Get the '06 (or '04 ) YZ450 CDI, and if you are running the stock shorty muffler, put something else on it.  You'll be amazed.

I have taken my stock muffler and removed the screens and made it like  PRO CIRCUIT one, then I will get the CDI from a 06YZF. I was also going to get the 06 YZF450 cams, I here they are better? 

They're actually the same cam grind and lobe profile, just timed a little differently for more top end.  The '06 cam set will increase low-mid range power a bit, but you should still try just the CDI first.  You can always add the cams. 

All of that is probably true, but he is working with an '08, which starts out with a big soft spot in the low mid range.  He might be satisfied with a whole lot less than the ultimate solution if he can get it working like a stock '06.

Thank you the info is great now just need to apply. Trying to buy the 06 CDI on internet.

Is the 04-06 CDI black box the same? I have found some on the internet? I see in a comment  that I can use the 04, so I gave him a bid. Thank you

Edited by Bill Birge

No, the '04 and '06 are two different maps, but not very much so.  Both of them bring on the bottom pretty hard, but the '06 is revs higher and is more manageable down low.  The '04 can be a little abrupt for many people as far as low end grunt.


Avoid the '05. It was sluggish.

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