So the horn on my CB550K hadn't been used in decades, if ever, and wasn't working. Sought some advice on this forum but there was no screw to access the inside as some suggested. Instead of possibly damaging the chrome cover by trying to remove it, I drilled a small hole in the back of the horn that allowed me to spray in some WD40. Let it sit a week, blew it out with the air hose today, ran power to it sure enough, it works! Really happy I can keep it original and some JB Weld should patch the hole nicely. Life is good.