I'm getting a metallic ringing kind of noise between 3500 and 4000 RPM. It can be duplicated standing still but I can't localize the sound. It only happens after the bike is warm. Any ideas?

Bill

Without hearing the sound or being able to localize it, my first guess is that something metal is vibrating at the RPM. check your exhaust pipes, exhaust shields etc to see if anything is loose or if the noise goes away when you touch it. Use an old towel or oven mit if you touch the pipes. Check license plate and anything else that might be rubbing metal against something.