VIN: KZ750B-000001 <-> KZ750B-014947
Engine: KZ750BE000001 <-> KZ750BE015032
Colors: Diamond Red
Characteristics that distinguish this model year from the ’77: Early non-indented right sidecover (changed to indented in mid-’76 model year), no starter lockout switch, color, and the ’76 tank pinstripe is rounded at rear, where the ’77 comes to a point
Characteristics that distinguish the ’76 / ’77 model years from the ’78 / ’79: Round front master cylinder, front brake caliper mounted in front of the fork leg (mounted behind the leg in ’78), 3-phase dynamo (changed to single-phase in ’78), separate regulator/rectifier units (changed to combo in ’78), and bushings (changed to needle bearings in ’78) in the swing arm. In ’78 there were also slight design tweaks in the output shaft assembly, recommended fork oil level, and there is some uncertainty about the recommended spark plug (B6ES/B8ES) between model years.
Other model characteristics can be found in the Kawasaki Service Manual.
This picture below (now owned by “Chris”, see comments below) features the earliest version of the B1, with the original un-scalloped sidecover. The bike appears to be fairly true to stock except for paint/stripes, missing grab rail, and an exhaust from a later model (perhaps a G1):
This B1 below (owner unknown) has the later ’76 sidecover, with the carved-out spot for the kick start lever at rest. It appears fairly stock except for a MAC exhaust (with stock headers and cross-over), and a re-upholstered (and over-stuffed) seat:
This B1 below is a U.K. model (owned by “Peter” from many forums, R.I.P.), featured here for the subtle U.K.-specific differences such as a mid-seat seat strap, the “z750” badge for the everywhere-but-U.S. model name, and rearward-mounted rear turn signals. Oh, and note the early non-indented sidecover again. Of course, it is re-painted, has custom-made exhaust (stainless steel, if I remember correctly), case guards, chrome gauge/clocks covers, and stainless brake lines:
NOTE: If you know (or are) the owners of the bikes above, please let me know so I can credit you correctly.