I have a 2002 WR 250f, that I am currently racing at as a motocross bike. I'm am thinking about changing the gearing, to better utilize the gearbox while circulating the track. Any suggestions? What gearing are you guys running?

Well the YZ runs 13/48 stock. I'd suggest 13/49 since the 48 is slightly tall depending on your weight. I notice it sometimes and I weigh 160lbs.

If your spacing is too wide too stay in the power you might want to get a different front sprocket. Go with one tooth less (12T). This will tighten up the gearing a lot. 52/13=4.00 vs 52/12=4.33 Dropping to a 12T on front should make first all but unusable on a MX track. I don't think you'll miss it though.

You have to remember that the WR gearing spaces the shifts out farther to get that 30 MPH faster top speed. First is much lower on the WR. Second is the same (but rear sprocket is different). Fourth gear on the WR is fifth on the YZ.

Hope that helps