I blew a fork seal on my Honda CRF250L, which covered my front brake in oil. Luckily I was able to stop. I had the seal fixed and cleaned the brake rotor with brake cleaner, but my brakes aren't as good as they were before the oil incident. What should I do?
The ultimate way to clean a brake rotor is to use a sand blaster. Besides improving performance, sand-blasting a rotor once or twice a year can actually double its lifespan.
For the average person, 400- to 600-grade sandpaper (or even a Scotch Brite pad works in a pinch) is much more accessible and still does a reasonably good job. Using small, circular sanding motions, work your way around each side of the rotor's brake-pad contact area.
Then, wash the rotor with soap and water. Brake cleaner contain chlorides that can leave a contaminating residue. Finally, use a clean, dry towel to wipe away any residue.
Additionally, you will need new, non-oil-soaked brake pads for your Honda CRF250L... luckily they are not so expensive...