I just purchased a 1996 CR 250, a few weeks ago.I found that it had plenty of bottom-end, but I changed the back sprocket to a 51, and now it's even better.It still has lot's of top-end though.
Carry more speed in, hit the brakes harder, clutch it coming out. Don't try and lug the motor. Depending on the tracks you ride, you might want to re-gear.