Went to start my XJ600f (1990 Pre-diversion) in the dark shed... Too excited to await the MOT. Suddenly, after charging battery, she would burst into glorious life and rattle a fair bit. Cam chain? not sure. Went like a train. Next day, plenty of life in the battery. Firing her up... there was a loud metallic clunk somewhere down below and then she would not start. What have I done? My first proper bike for 20 years! Have I knackered her before we got going? Any ideas?