H-1 Mach III 500, introduced in late 1968  with distributor.
In 1972, the 750 Mach IV (H2) was introduced and was essentially a scaled-up version of the H1 500

In 1974, the 350 cc S-2 was expanded to a 400 cc S-3. In addition, the model range was toned down in performance. The H-2 ceased production in 1975, and the model line became the KH series in 1976. United States production stopped in 1976, while the 250 cc KH-250 and 400C KH-400 continued in Europe and elsewhere until 1980.

The S-1 was popular for some time as a budget performance bike in England because of its small size, and the fact that at this point in time it was legal for learners to ride. The entire S series of motorcycles used breaker point ignition, which was more reliable than the early CDI ignition and much cheaper to repair or replace.

1969 H-1 500 cc white w/blue stripes, distributor CDI ignition, drum front brake, "Mach III 500" badge on side cover and "electronic ignition" decal on oil tank. Late 1969 saw the introduction of the Charcoal Grey model

1970 H-1 500 cc red w/white stripes on the fuel tank.

1971 H-1A 500 cc, style redesign without the Mach "III" badge, blue with stylized stripes on the fuel tank.

1972 Entire line introduced, intended to be similar in style, with the "swooping" racing stripes on the tank that distinguished the triples. S-1 250 cc, white w/green stripes.also in red S-2 350 cc, red,also in white drum front brake H-1B 500 cc, orange, disc front brake, CDI dropped for breaker points, and a front disc brake. The H-1C is believed to have been made by Kawasaki factory using up its leftover parts. It had CDI instead of the points on an H1B and also a front drum brake as opposed to the disc on the earlier H1B. Also a few cosmetic changes. H-2 750 cc, Blue or Gold - Gold versions were in the early production run and went to the home market of Japan, Australia / Southern Hemisphere and Europe but not to the U.S.A., front disc brake, CDI ignition with one igniter unit per cylinder.

1973 S-1A 250 cc Gold or orange S-2A 350 cc Orange or Blue. H-1D 500 cc Adopted H2's CDI ignition and the styling that would be used on the later 1974 models. H-2A 750 cc Purple/Gold.

1974 All models restyled with a new cleaner design that resembled the Kawasaki Z-1, with an instrument "pod" rather than separate instruments. All models revised for more civilized performance at the expense of raw power. S-1B 250 cc green, front drum brake. S-3 400 cc blue or red, disc front brake, restyled cylinder head design for better cooling. H-1E 500 cc green or red. H-2B 750 cc brown/green.

1975 S-1C 250 cc blue. S-3A 400 cc Green or Red. H-1F 500 cc brown or Blue. H-2C 750 cc red/purple.

1976 H-2 dropped from line, models renamed "KH" to match the "KZ" line of four strokes. KH-250 250 cc. KH-400 400 cc. KH-500 500 cc.

1977-1980 Only surviving models are the KH-250 and KH-400. KH-250 250 cc.