The B1 was first introduce late 1976 and a future classic was born.

The B1 had a dual overhead camshaft engine with 2 valves per cylinder and was rated at 64 hp. Its light weight and good handling made it a hard bike to beat even for the bigger capacity bikes. It was intended to take up the fight with the 750 bikes. And it almost did. Only the strongest 750 bikes (Honda CB and Suzuki GS) was just slightly ahead. Even compared to the Z1 it was just 10miles/hour slower and much easier to drive at top speed.

The B1 can be easily  recon iced by the front brake caliper in front of the fork's and its round front brake master cylinder. The engine is all aluminum color and the engine casing had no ribs.  It was offered in three colors, candy super red,  candy emerald green. and  Candy Emerald Blue. (not quite sure about the blue one)

Z650B2 B2/A 1978

The B2, look much like the B1, but the new model have some notable changes. Most notable change was moving the front brake caliper behind the forks. This was also done on most all other Kawasaki's in 1978. There was a new triangular master cylinder replacing the previous round one from 1977. The generator cover was new, see picture, and the ignition engine cover slightly different from the B1. But a lot of smaller changes was done, there was a minor updates to parts like the battery case, speedometer cable was modified, fuse assay was new,  there was a new vacuum fuel tap, and a slightly different gearing in the gearbox. The charging system was changed from a three-phase system to a two phase and the regulator and rectifier was now a combined unit. (regulator with cooling ribs) Two colours were offered for 1978, luminous dark blue or luminous burnt red.

The B2/A was much the same as the B2, not sure but its probably a late production B2. There are some minor changes like changed carburetor assy and some changes to carburetor internal parts. And right hand switch gear got (another) lightning switch. You can find the changes in the parts list.

Source: Cycle World.

Z650B2 Ryan Pedersen, Denmark

Luminous Burnt Red >

Z650B3 1979 & Z650B4 1980

The B3, last of the B series. The easiest way to tell if its an B2 or B3, the B3 had "small" letters in the Kawasaki badges and the B2 had "big" letters like KAWASAKI.  The colors was a return to the one for the B1 model, witch was more popular then the B2 color scheme. This time the red color was described as candy persimmon red.

Some minor changes was also done:  The cam-chain tensioner was modified. New wiring harness. New engine top cover, new square front and rear footrest. The switchgear was slightly different, small changes to the exhaust system etc. Fore more details look in the parts list.

The Z650-B4. The service manual list it. And it have the same specifications as the C4 but with B model wheels and brakes. Its listed as a European only  model.  Anyone???

 * /Source: www.kawa-z650.de

* /Source: www.kawa-z650.de