Motorcycle History: Kawasaki Triples

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Motorcycle History: Kawasaki Triples

Each week RideApart looks back at key milestones in motorcycle history from technical innovations to significant model introductions to racing successes and, of course, some of the disastrous things we’d rather forget. This week we look at Kawasaki’s two-stroke triples that were introduced in 1969.

After a nearly a decade of the motorcycle industry being dominated by the British manufacturers, Kawasaki took everyone by surprise by launching in 1969 its first triple cylinder bike. The Kawasaki Mach III H1 500cc had an air-cooled, three cylinder two-stroke engine. There were two exhaust pipes on the right side of the bike and one on the left and while most other manufacturers had been developing four-stroke engines, Kawasaki took the plunge and came up with its triple two-stroke.

Kawasaki 750
Kawasaki 750

Right from the start the H1 was one of the quickest motorcycles of its time and to underline how fast it was to the motorcycle media, Kawasaki took the H1 to a drag strip and factory test rider Tony Nicosia ran the quarter mile with it in 12.96 seconds at 100.7 mph.

While it was apparent that the Kawasaki 500cc triple was a fast bike with a high power-to-weight ratio, there were a couple of issues.  Poor drum brakes front and rear meant that it didn’t stop too well and its handling was best described as pretty odd. Some people went so far as to describe the bike as dangerous because of its unexceptional frame design and among motorcycle enthusiasts the bigger capacity Kawasaki triples earned the dubious nickname of the ‘Widow Maker’.

Kawasaki Triples 750
Kawasaki 750

However, based upon the initial positive reception of the H1, Kawasaki rolled out a range of triples in 1972 including the S1 (250cc), the S2 Mach II (350cc) and a 750cc version called the Mach IV that sat alongside the 500cc H1.

Despite the impressive line-up of the new models, the handling problems apparently didn’t go away. Owners reported that the bikes had speed wobbles and a tendency to pull wheelies, which for those who liked that sort of thing, it wasn’t a big issue, but on the bigger engine versions it tended to do this when the rider was least expecting it. Some claimed the Mach IV was capable of pulling a wheelie at over 100 mph.

Kawasaki 750
Kawasaki 750

The result was that some owners got hurt (or worse) on these bikes and consequently insurance premiums for Kawasaki triples started to increase. This in turn had a direct affect on sales and marked the death knell of what was really quite an innovative and fast motorcycle for its time.

By the mid-1970’s motorcycle manufacturers were coming under increasing pressure to make their engines meet more stringent emission requirements. This was to prove the downfall of two-strokes and by the middle of the decade nearly all two-stroke motorcycles had been discontinued.

Kawasaki 750
Kawasaki 750

The KH500, a development of the original H1, was the last Kawasaki triple model sold in the U.S. in 1976. Thereafter Kawasaki returned to four-stroke engines on its bikes

Since the demise of the Kawasaki triples, some 40 years ago, they have become something of a collector’s item with many fetching large sums of money, despite their handling characteristics. Why? For their time, they were fast, innovative and looked darn good.

  • Reid

    My dad, an amateur motocrosser in his younger days, claims that back in the day he rode an H1 for all of 15 minutes before he swore off street riding forever. He’s 55 now and he has only just started to reconsider. Sounds awesome to me!

    With Yamaha bringing out the FZ-09, I’d love for Kawasaki to get in on this fight too.

  • martin

    I had a KH350 in the late 70′s and when it ran smooth it was a lot of fun, trouble was it was a bitch to tune so never ran that smooth. Sounded great though.

  • Robert Horn

    One of my favorite references for superbikes of that era:

    • Mark

      That is a great article!

  • Jesse

    My dad had an H1 Mach III “Widowmaker.”
    He owned many motorcycles (and janky British and German sportscars) after it, but swore that Kawi was the single most terrifying thing he ever drove.

    • KeithB

      I can agree with that!
      Didn’t pull al that well until around 5500 rpm then it was a whole lotta FFFFFF.K -ME!

  • Pablo Perez

    Never rode the Kawi. I did ride a GT550 (the Suzuki equivalent). All I remember is the funky power band, the crappy suspension, and the ridiculous brakes. That and it was a sharp looking bike, even ~15 years after it was built.

  • Mister X

    We called them Flexi-flyers back in the 70′s, beautiful bikes and they were damn quick, the first time I went 130 MPH on a bike it was a pearl white (purple undertone) 750 H2 with black Denco chambers and proper jetting.

    It was test riding a buddy’s H2 for sale and it scared me with a slow speed third gear wheelie from real low on the Tach when I gassed it from a green light, it was insane, I knew if I bought it I would kill myself.

    Hmm, I see the H1 did 12.96 in the quarter mile, my Kawi Bighorn 350 ran 12.75 something at Fremont in the early 80′s and it’s a single.

  • Don Fraser

    My 3rd new bike was a blue ’72 750, put 8000 miles on it in the year that I owned it, wheelied it pretty much every time I passed a car, 23 mpg, vibrated like crazy, little wiggly in the corners, loved it. Payed $1200 and sold it to a friend for $1000.

  • Jimmie Davis

    Bought a new H1 in May 1969, then bought an H2 in Dec 1971. Yes the handled really bad, even worse if you rode them past their limits. They are the bikes that taught me to be smooth. My H1 could get as low as 22 mpg, the H2 18 . . . We called them Wobblesaki’s o_O

  • A P

    Nasty reputation was well deserved, had an H2 for a season in the late 1970′s. Easily the scariest bike I’ve ever owned, and that includes an ’80 GS1100E and now a ’06 CBR600RR.

  • gravit8ed

    I’m told my existence in this universe is no small miracle, given my father and uncle’s passion for all things ‘smokey triple’ Kawasaki.

    Also, that a fat leather wallet literally saved my dad’s ass one sunny afternoon in front of his high school, my mother, and most of the neighborhood, due to that little issue mentioned wherein the front wheel was not friends with the pavement. I hear that story just about every other time I stop by mom’s house on the KZ, lol/

  • ImNotTheWalrus

    I was a novice when I bought a 70 Mach 3 in 1971 having only ridden 90cc Honda’s in Japan for a few months.So I didn’t know handing and brakes from my azzss back then but the Mach 3 was insanely fast I likened it to riding a chainsaw and the front end would lift in the air a lot although it made people think I knew what I was doing,I didn’t and being 21 at the time,I’m lucky I’m still here.