Ten days with a 1975 Kawasaki S3 Mach 2

Enlarge Image Image Gallery Though not as raucous as its bigger brothers, the Kawasaki S3 Mach 2 still has plenty of attitude. Photo by Richard Backus

Kawasaki S3 Mach 2
Years produced: 1974-1975
Claimed power: 42hp @ 7,000rpm
Top speed: 97mph (period test)
Engine type: 400cc, air-cooled, two-stroke inline triple
Weight (dry): 155kg (339lb)
Price then: (1975) $935
Price now: $1,000-$2,000
MPG: 22-35
Oil consumption: 1/2qt two-stroke oil during test
Beginning miles: 2,925
Ending miles: 3,283

If you’ve never ridden a classic two-stroke, you owe yourself the experience. Generally smoky, smelly and loud, they pay back in spades with a power rush you have to feel to appreciate. And that’s just with a healthy single: multiply that count by three and the payback is a thrill a mile. 

We sampled a 1975 Kawasaki S3 Mach 2 - one of the tamer (and better) of Kawi’s three-pot oil-burners over the course of a few weeks - and when it was all over, we hated to give it back. Our test bike is the kind of machine we all dream of finding. Its first owner rode it a little over 1,000 miles before passing it along to his son, who then parked it in his garage where it sat until 2006. Its current owner then acquired the bike for $150. Yes, just $150. But more on that later. 

In the beginning…
Before 1969, Kawasaki was a just a bit player on the American scene. With a quirky line of two-stroke singles and twins, its biggest standout was its BSA-clone W1 and W2 650 twins. But that all changed when Kawasaki introduced the three-cylinder Kawasaki H1 Mach III in 1969. With a claimed 60hp from its 498cc three-cylinder, two-stroke engine, it was just the thing for a power-hungry market. Suddenly, Kawasaki was no longer an also-ran; the Mach III’s 120mph top speed and 0-60 time of 4 seconds made it the king of the drag strip and the fastest production motorcycle on the market. And the market loved it. 

Quick to capitalize on the Mach III’s success, in 1971, Kawasaki duly introduced a trio of triples focused on that bike’s two-stroke theme. First up for the new additions was a bigger and badder 750cc variant, the Kawasaki H2 Mach IV, followed by the 350cc S2 Mach II and finally the diminutive 250cc S1 Mach I, all sold as 1972 models.