wr250f timing vs. cdi black box


Feb 12, 2001
got a question. many wrf folks, on the 250 and 400/426 sides, have retimed their bikes to the yzf spec. performance in certain areas is improved, and there doesn't seem to be much downside. but can a yzf-timed wrf engine *really* perform like a stock yzf? the reason i ask is because i'm not sure that the two different bikes share the same mapping for their CDI units. in other words, is the CDI's 3D contour map (timing+throttle opening+rpm) the same for the wrf and yfzf engines? do the yz250f and wr250f use the exact same black box? is the computer on a yzf timed wrf operating under some incorrect assumptions?

rich, what do you think?

the wrooster


Aug 22, 2000
The part number is the same for both, I believe (I was looking them up for a customer awhile back). I'll check it out at work on Monday and give you a real answer then!


Feb 10, 2001
wrooster--This isnt an answer to your question but since the subject of CDI contour mapping had come up l thought you might be interested in this.
I was riding at a club MX a few weeks ago (in New Zealand) and noticed a friends YZF250 had an accessory CDI unit running on his bike. He had been having a lot of starting and apparent ignition problems and had forked out for a Wolf CDI, a unit made in Australia that allows the rider to programme the 3D ignition map for various kinds of riding. He had a handle bar mounted switch near the throttle that allowed him to choose between a 3D and a 2D map while riding so if he needed a little more power at high revs it was available at a quick jab of the thumb. He said there was a noticable increase in power from the OEM unit.
I`ve not seen any reference to these units in previous DRN posts and l have no idea if they are sold in the US either, so please excuse my ignorance if you already know about them. You can find more info at www.wolfems.com.au