paarish8
I have a 99 WR400 that I ride on both trail and track. Although, I prefer my XR350 on trail, the WR works very well.
On the track the WR is great. I would recommend changing the tank and seat to the YZ style. It lets you get closer to the front, makes the bike steer better in the corners. Also, keeps you from busting your nads on the tank when you come up a little short.
There are a lot of free mods that you can do to the WR engine to make it run like a YZ on the track and still work on trail.
Just my $ .02