Below is the late Rick Hocking on CB750, before the AMA banned it. I once sat in a Vegas jacuzzi with Rick. I wish I'd made the time to interview him. G
UPDATE: Roger F got in touch to say 'It's either a 500 or 550, probably a 500 from the looks of the stock paint on the tank. The 500/550s had vertical cylinders, while the 750 cylinders had a forward lean to them. Either way, the inline fours were a handful for all but the best experts to ride.'