Every Kawasaki two-stroke triple shared the same three-cylinder layout, but the family ran from a 250 to a 750. The first, the 500cc H1, reached buyers for 1969, and the last KH250 left the line in 1980. In between, Kawasaki sold the triple under both the Mach and KH names. Here are seven of those models.

Model years shift a little from source to source, because markets and catalogs differed. So the years below are model years, and we note where references disagree.

1. 1969–1975 Kawasaki H1 Mach III 500

The H1 started the whole line. Kawasaki introduced it in September 1968, according to the UK owners’ site Z-Power. It made 60 bhp from 500cc and used capacitor discharge ignition. Z-Power also credits it with nearly 120 mph and a 12.4-second standing quarter mile.

That speed came with a reputation. Writer Lee Wilcox at Curbside Classic notes that the power arrived suddenly around 6,000 rpm on all the triples. He also lists the H1 at 60 hp at 7,500 rpm, matching the Z-Power history. Both sources run the 500 through 1976, but by then it wore the KH500 name (No. 7).

2. 1972–1975 Kawasaki H2 Mach IV 750

When rivals caught up with the H1, Kawasaki answered with a bigger triple, Curbside Classic says. The H2 Mach IV made 74 hp at 6,800 rpm from 750cc, according to the same feature. Meanwhile, Z-Power quotes 74 bhp and a top speed of 126 mph.

Start dates differ here. Z-Power runs the H2 from 1971, while Curbside Classic begins it in 1972. Both agree it ended after 1975. The final H2-C came in Candy Super Red or Candy Purple, Z-Power says.

3. 1972–1975 Kawasaki S1 Mach I 250

The S1 put the triple layout into a quarter-liter bike, which Curbside Classic says targeted younger riders. Kawasaki revealed it in 1972, according to Classic Bike Guide. The bike then ran through S1, S1A, S1B and S1C versions until the 1976 rebrand to KH250.

Z-Power’s S-series guide says Kawasaki claimed 32 bhp and a top speed of almost 100 mph. Meanwhile, Curbside Classic lists 32 hp at 8,500 rpm. The S1 also stopped with a twin-leading-shoe front drum rather than a disc. Classic Bike Guide adds that press bikes were allegedly “massaged” to crack the magic ton.

4. 1972–1973 Kawasaki S2 Mach II 350

The S2 lasted only two seasons. It replaced the A7 Avenger 350, according to Clement Salvadori’s Rider magazine retrospective. Its engine used an almost square 53 x 52.3 mm bore and stroke. Kawasaki claimed 45 hp at 8,000 rpm, but testers could not get it to 100 mph.

Still, the S2 was light at about 330 pounds dry and cost just under $900. Early bikes used a drum front brake, while a disc arrived late in 1972. For 1974, Kawasaki enlarged and detuned the engine to create the 400cc S3, which later became the KH400 (No. 6).

5. 1976–1980 Kawasaki KH250

For 1976, the S1 became the KH250. Apart from colors and cosmetics, the bike was ostensibly identical to the S1, according to Bikesales. It displaced 249.5cc. Power, however, dropped to 28 hp at 7,500 rpm, and the first B1 version gained a 226 mm front disc.

The KH250 outlived every other triple. Bikesales says Kawasaki produced the final KH250-B5 in 1980. That last version came only in Kawasaki racing lime green, according to Z-Power’s KH guide.

6. 1976–1980 Kawasaki KH400

The 400cc S3 took the KH name for 1976. According to Classic Bike Guide, KH stood for Kawasaki Highway. It describes the KH400 as a larger, updated and slightly less exciting S3. Kawasaki may have stopped building them in 1977, the magazine says, but it kept the model in UK catalogs until 1980.

Emissions changes cost the KH400 4 bhp, so it made 38 bhp at 7,000 rpm, Hagerty UK reports. It also gained electronic ignition. In a road test, the bike averaged 31 mpg, and Cycle World recorded 98 mph.

7. 1976 Kawasaki KH500, the Last 500cc Two-Stroke Triple

The H1 ended its run as the KH500 A8. It displaced 498cc and made 52 hp at 8,000 rpm, according to Motorcycle Specs. The same source blames anti-pollution rules for the drop from the H1’s output. The gearbox also changed to a first-gear-down shift pattern.

Z-Power also quotes 52 bhp and calls the KH500 the final evolution of the H1 line. Motorcycle Specs adds that 1976 marked the end of the 500cc Kawasaki two-stroke triple after eight years in production. After that, only the smaller KH models carried the three-cylinder idea forward to 1980.

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This article was created with the help of AI and was reviewed and edited by Fast Lane Only editors before publication.