Honda 4-cylinder Dirt Tracker

Summing up INWYR, IHYRI - I spotted this on the excellent Poppawheelie blog.

How tough does this bike look? I don't know if it's a 500 or a 750.
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.'