1990 XLH1200. I'm hearing some chatter in higher gears when I back off the throttle. I really hear it when going downhill and the engine is acting as a brake. I don't hear it so much in lower gears and not at all when in neutral. Don't hear when on the throttle. My first thought valve chatter but oil level seemed fine. Then I thought possible loose primary chain. I tried to adjust that but still hear noise. Any ideas?