I am one of the guys who had the plug fouling problems (01 YZ426). The new CDI instantly cured my bike. The bike would only run 10-15 minutes per plug. The problem seemed temperature related; the colder it was, the quicker it would foul a plug. With the new CDI, I have had the same plug for 20 hours, at least. And the YZF runs great. This was my second YZF, so it was not like I didn't know how to start, jet, or maintain the bike. Anyway, my dealer swapped my CDI with an 01 bike off the floor. But another TT guy had problems (like you, he also had a friend with an 00), so I checked with my dealer for him. The mechanic at my dealer told me that the 00 CDI was the same as the 01. But then later someone on this site told me that the part #s were not the same. Why not check YOT website to verify? You might search the topics under "fouled plugs=foul mouth" to get the history on this problem.