Original Widowmaker: Kawasaki H1 Mach III

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Just when we think we’re the hippest and baddest generation that ever lived, you find out guys were riding Kawasaki motorcycles in the 70s that could rip off the quarter mile in under 13 seconds. This 1970 Kawasaki H1 Mach III 500 here on eBay is a recent garage find, discovered when the seller went to purchase a Citroen DS project locked away in Los Angeles. Can I just say, I hope I’m as cool as the original owner someday? Thanks to Barn Finds reader Jim S. for the find.

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In the late 60s and early 70s, it became clear the US represented a major market for motorcycle sales, and customers just wanted more. Brands like Kawasaki and Honda saw this and began engaging in somewhat of a horsepower war, seeing who could crank out even more juice from already high-strung motorcycle engines. The H1 Mach III featured a three-cylinder two stroke with an impressive power to weight ratio and the ability to reach a 115 m.p.h. top speed.

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This example is believed to have been stored in the garage for many years, with its genuine California black plate providing a clue as to when it was last on the road. The seller has confirmed the engine will kick over, but he’s otherwise left it as he found it (and in this instance, I think that’s a good thing). He also purchased another bike in the garage which had just 3,000 miles on it and is believed to have been the replacement for the Kawasaki, which shows 11,000 miles on the odometer today.

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At the time of its introduction, journalists felt that while fast, the H1 was a bit too skittish at the limits to ride confidently. I don’t think that deters me from wanting to own a bike like this, however – to ride something so raw that requires your complete attention is a phenomenon that’s been neatly excised from almost every vehicle on the road today. And given the makeup of the original owner’s garage, I can’t help but see adding this bike to your fleet as a form of good will, ensuring your collection will remain interesting and significant even as innovation declares its contents dangerous and rudimentary.

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  1. Joe Emmert

    Had 2 of these. Got out, having used up 7 of 9 lives. Front end, brothers 350 triple, actually scarier, as it came up even quicker. Skittish at high speed is a kind comment. More like totally squirrelly. Friend had 750 triple. That’s the best one. Added weight helped stability, and nothing of the era could catch it. I sure tried.

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    • r spreeman

      I have an old book (from the 70’s) which describes the handling of these bikes as you just did – apparently unsafe at any significant speed. Squirrelly is an accurate description indeed.

      The problem with a lot of these old Japanese bikes is that the aluminum pits, the chrome is poor quality and often infused with rust, basically it’s murder to try and make them look great again. Meanwhile, for all their quality flaws and ‘vintage’ design, a Harley holds up so much better.

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  2. Blindmarc

    Owned several of these, and it’s 750 big brother. They’re quick, but cornering was challenging at speed. I went to the 2 stroke yamahas and extreme large bore inline fours.

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  3. Robert White

    My Bullwinkle killing fishing buddy has the 750 H2. He rebuilt it entirely and drives it to antique bike shows every year. They are extremely fast bikes and only seasoned riders should ride them IMHO.


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  4. Dean

    A friend had one of these in 70 or 71, and let me “take it for a spin” one night. As it approached redline in first (very very quickly), I speed shifted into second and then fought to bring the front wheel back down onto the pavement for the next several feet, or perhaps several blocks – I was too scared to look around much to determine how far or fast I was going. It was almost as bad cracking the throttle in third (after a much more reserved shift). Widow makers indeed – and I wasn’t even old enough to be married, let alone make someone a widow. These bikes were so different than the BSA’s or Triumphs of the day, or even the high revving 2 stroke trail bikes I was used to.

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  5. Ken

    Was saving for a new Honda 350 in March of ’72 when I saw a sale ad for a new Kawasaki Mach III 500 for $1045, which was exactly what I had, so I rode a new orange one home with the Iowa ditches still full of snow. The power band at 6000 rpm was frightening, and it would take off underneath you with your arms extended 10 feet, cartoon style, and you hoped you didn’t have loose gravel under you when you hit that mark on the tach. I was 19 and topped it out regularly at 115 mph, unable to keep up with my buddy whose 750 Suzuki Water Buffalo would top out at 135 mph. Sold it that fall when I went in the army, and am happy To have survived both.

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  6. gejettest

    The photo of the keys in the ignition is surreal.

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  7. Doc

    Wow Had one for a very short period of time. Smoked the then new 750 Honda.
    My brother still wears the scars of its final run.

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  8. Pfk1106

    Friend had one. I had a 650’bonneville. He could out run about anything in a straight line, but he couldn’t stay with me on curves. Section of road called 7 sisters in Maryland with a long straight away at one end. The curves are nicely banked, but he lost it on the first curve off the straight . He lived, with a shorter right leg .

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  9. GAS2HI

    I had a H1 and as other folks have mentioned, it was a bike that was a hand full. At the time I topped 120lbs and took it the drag strip regularly. Best ET was 12:79. The key was keeping the revs up as you came out of the hole. Would go 0-60’in 4 secs or so, took 800 ft to stop!!! Best going in a straight line, but I left most 900 cc HD ” CHs in the dust. They always gave me a hard time on the way they sounded, but I said I hope you hear that terrible sound as I pass you…😀😀

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  10. pappy2d

    They were called flexible flyers for good reason. When they “came up on the pipe” the frame bent in unexpected ways. 70’s tire technology and a single disc brake assurred a thrill a minute. The RD series Yamahas were a better balanced package.
    The fun per dollar ratio though…. really cheap, exciting fun.

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    • Paul Newbold

      Yes they came with a huge hinge in the frame. Like so many Japanese bikes of that time, over powered, under framed.

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  11. vern

    Anything on the Citroen ? did he buy , pictures, sedan/wagon,green/red fluid rust level?

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  12. geomechs

    I remember when these hit the ground back in ’69. They were quite a sensation. I believe it was Cycle Magazine did a feature called the Super Seven Shootout (or something to that effect). It seems to me that the Mach III was the smallest bike there but still came in an impressive 2nd. It just couldn’t take out the Norton Commando. Never rode one myself so I don’t know how they went. I was told (like previously mentioned) that they were hard to beat in a straight line but their cornering capabilities left a lot to be desired. Nice bike. Looks fairly complete although I have my doubts that the front fender is original…

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  13. funfunfer

    I can echo Dean’s experience. I had cosigned a loan for my ex’s brother and rode the bike one time after he had added tuned expansion chambers. Incredible sound, but front end lift in 4th caused me to rethink my mortality. The bike came back to me about 10 years later a storage facility dumped it. Can’t for the life of me figure out what I finally did with it.

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  14. angliagt

    I remember sitting in class in High School in the early ’70’s,
    & hearing one wringing it out outside.
    These are bringing stupid money now,& now that I’m older,
    don’t think that a two-stroke novelty would last long.

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  15. lostboy

    Great article. How bad was it up top? I had a buell xb9 that shook like crazy above 80mph. I hear that’s what they all do.

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    • Doug Towsley

      Buells should not shake, if it did something was wrong. A damaged tire can do that, but Wheel bearings are well known to have issues on them, Could be any number of other issues. A Buell DOES have steep steering rake and CAN be squirrely so most people fit steering dampers but a damper can also mask a problem. Proud owner of multiple Buells (1998 S1. 2002 S3. 2005 XB12SCG, 2008 XB9SX, and selling off my other Buells a 2003 and 2007 XB9 Firebolts)

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  16. stillrunners

    Damn time to get my street H1 and my H1 drag bike out on ebay ( which I’ve been saying for about 4 years now) – both of mine are 1972’s which was the first year for a disk brake so yes the front end on this one is not right but a damn nice bike not locked up with the factory keys…also have the early motor with the rotor cap by your shin….great fun in the rain if the boot is bad ! And if you wanted to know what I did today I started moving my R5’s and RD400’s to their new home….which will be a nice trade off….

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    • Greg A Yancey

      I owned a 1971 Blue and a 1972 Orange…the disc brake and heavier forks did make the 72 a somewhat better handling and stopping bike. And the styling and color on the 72 was simply drop dead beautiful. I was told the 72 was supposed to be slower because of the removal of the troublesome CD system with standard points/condensor ignition (a one year stop gap method while Kawa redesigned the CD and reintroduced it in 1973.) My Orange didn’t get that Memo I guess as it would actually turn faster 1/4 miles than my blue. Enjoy your rides.

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  17. junkmanMember

    Wingadingading!!! Drum brakes, high speed wobble, oh my God what a fricken scary absolute blast. Yeah I had an early one, and proud to say never dropped it or lost a stop light challenge.

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  18. Doug Towsley

    I have had a few of these triples, and currently have a 350cc version (S2). All the stories about the bad handling and frames are true. One of the best things you could do was get a Rickman Chassis (Road race version) and stick the powerplant in there.
    These are super in demand now with collectors and I know people who scour the countryside looking for them, Most get shipped to Europe and Asia. Put up an ad on CL for one and you will be bombarded by pickers in minutes. This guy will do very well for himself on this deal. KA-CHING!!!! $$$$$$$$$$$$$$$$$

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  19. St. Ramone de V8

    Just knew that there would be lots of cool stories about these. Never owned one, but rode one several times, and agree with everyone about the ride! Thrilling, scary sometimes, and sketchy handling. Widow-maker! Love it.

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    • Doug Towsley

      Stories? We got stories! So, I have a friend and an old shop customer who told me a great one. He is/was a member of a 1% MC patch club, and pretty intimidating guy if you dont know him. Likes all kinds of motorcycles, but of course, while wearing his club colors is riding the stereotypical HD Chopper. So one day years back (early 90s) He and 2 club brothers were on a major interstate freeway here locally. He said off to the side they could see on the entrance ramp a bright Green bike merging onto the freeway. Dave said they were doing 65mph and the Green bike was easily doing 75mph. He said he saw a puff of smoke as the guy cracked open the throttle all the way and he said even at that clip the bike rocketed forward and the front end came up just as quick. Bike fishtailed, went into a tankslapper wobble quickly and down he went. KE-RASH! Smoke,,,sparks and body tumbling.
      Being the experienced bikers they are, Dave gave the signal, the rest of the club guys spread out and controlled traffic and Dave and another guy gave first aid. The Green Meanie rider survived with road rash and a lot of bruises and abrasions. Bike pretty trashed but salvageable,. After all the excitement and mayhem died down Dave puffed out his chest and proclaimed ” I WANT one of THEM! Thats a BadA$$ bike!”
      And he said the same for years afterwards. Now most people might be inclined to be intimidated by such a bike but to Dave, A bike with that kind of raw power was pure attraction. Nowdays you can kill yourself quite effectively with a HyaBusa or other rice rocket, but a brutal powerband like these bikes have caused a lot of wrecks.

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  20. Doug Towsley

    Well, stories you got them, With the epic tales of such a bike such as this, I would be remiss if i didnt point the erstwhile readers of this esteemed forum to one of the epic scribes of gearhead fandom. One of my favorite authors. Hunter S. Thompson (RIP)
    Here is one of greatest tomes on powermad motorcycles and riders.
    The Song of the Sausage creature! (Enjoy)

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    • Greg A Yancey

      Thanks Doug…this was an awesome report! The mentions of Kawi Triples and Sonny Barger brought back many memories (some good and some…wellllll)….I grew up in Richmond, Ca and the Angels were a part of our landscape…I have been to Sonny’s house in Oakland and was acquainted with his VP, Big Red. The term ‘cafe racer’ is one close to my heart as, indeed, I are one!! Many trips down Hwy 1 to the Rock Store back in the day, clip-ons guiding the big Kawi through awkward turn after awkward turn…and I lived to read your post…pretty Awesome! My eyes and reflexes at my age of nearly 70 have brought reality into focus and I now content myself with Cruiser Life…but the spirit still idles within only awaiting the day that sanity may yield to long lost lusts!

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  21. Paul R

    And then came along the KZ 900..What a bad ass in the mid 70’s!

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  22. Doug Towsley

    If you can find one of these bikes, As i said most people put the powertrain and other parts into a better chassis (Rickmans were great) But there was several companies that made chassis for these.

    However, There IS something about some of the period Kawasaki racers and while i have sold off a lot of my projects I kept a KZ750B which is a twin cylinder 4 stroke, not as cool or fast as the Triples or the KZ900s (Which also are big money collector bikes now) But I ordered the body work from AirTech and restyling mine to look like this. For a lot of vintage bikes they make some cool body work See: http://www.airtech-streamlining.com/kawiz/H1H21969-76.htm

    Modern fuel will melt some of this body work but what many people are doing is installing a metal bladder.

    Theres a local guy as well who does some great body work as well, Glass from the Past (GFTP) See:


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  23. HoA Howard AMember

    WOW!!! Count me in on this one!! ( See? To people that don’t like what BF’s has become, it’s all about stuff like this. Look at the memories these threads rekindle)
    This bike proved, for the Asians, the “Super Bike” race was on!! Sure, Honda brought civility to the table with the 750, 4 cylinder in ’69, but Kawasaki upped the ante, and the “crotch rocket ” was born. A guy across the alley from me, traded his BSA Thunderbolt on an orange Kaw 500. It, as stated, was a handful. Like Dean sez, the power band caught me off guard, as I remember, it was a dog until about 5 grand, then up came the front wheel. Clearly, it was too much motor for the bike they stuffed it into. I experienced the “death wobble” too, and was too afraid to go any faster. The cylinders sticking out the sides did affect the handling, but this bike was designed to do one thing, go fast in a straight line, and it did. These had a habit of sticking the center cylinder, as they ran hot. I heard the 750 triple, was even more of a handful, but may have been slightly de-tuned, as they weren’t as fast as you’d expect a bike like this with a bigger motor would be ( still darn fast though) When the Z-1 900 came out, basically replacing these, they were a much more refined bike, and I’d love to have an original Z1-A, this not so much. THanks for this, Jeff, and what BF’s is all about, memories. ( Where’s Z1 rider?) http://classic-motorbikes.net/wp-content/uploads/2015/10/z1.jpg

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    • Alan (Michigan)

      THAT EXACT (color, etc.) BIKE was bought by a co-worker friend when they came out. He was not a big guy, but he certainly learned how to wheel it with amazing skill. So many stories, recollections of nutty antics that were death-defying as far as the rest of us mortals were concerned.
      He got married, and sold the bike before his first child was born, choosing to “be around” without taking those chances anymore. A wise decision for a young man to make. It has been decades, and I wonder if he ever wishes he’d just kept it and put it away in the dry corner of a garage. Never mind, I know the answer to that.

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  24. Chris A.

    I needed a winter car back in mid 70’s and a friend sent me to look at a 1966 Corvair 140 coupe. Turns out the seller wanted the garage cleaned out as she was moving. Next to the Corvair was an H2 750 that she said didn’t run. So I asked her if that went with the Corvair. She said I could have it for $100 as it had to go. I remembered the stories and my questionable riding skills and took a pass. On summer nights you could hear these bikes being wound out on 490 East out of Rochester to Victor, the sound of the 3’s coming onto the pipes was just a pure scream. As I recall, the front fender on 500’s was chromed, maybe that was later versions.

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    • HoA Howard AMember

      Hi Chris, I thought so too, on the chrome fender. I wonder if this is a very early one or “home version”. Anybody that’s not familiar with these, check this out. Hang on!! ( note bald back tire!)( also note, make sure you are in a straight line before gassing it) https://www.youtube.com/watch?v=dAd4XpXrpnc

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      • Metalted

        Sweet bike for sure,
        And agreed , it’s a point and shoot , bike for sure.
        Love the old jap. Bikes.

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      • Joe Emmert

        Thanks for posting that. Sound brings back a million memories.
        Warm summer nights of immortal youth.

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      • HoA Howard AMember

        You’ll note, this guy has more grapes than I do. He hit 100 on one of those straights. Didn’t notice any death wobble, though. Still would rather have the Z1. Just for comparison, here’s a Z1. I’d have no trouble going 100 on this. I remember, they would cruise in 3rd gear at 70. Look how fast the speedo on the left jumps (sorry, little long, but you get the idea. Ain’t no “ring-ding”, for sure. Gotta get me one of these). https://www.youtube.com/watch?v=ivUkFfAw9S4

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  25. pappy2d

    These bikes could be compared to a stick of dynamite. The fuse lasted up to 5000RPM. Back in the 70’s, when I was still bulletproof, it made sense to start with the 750 version. Fly cut the pistons, mill the heads, feed the beast more fuel and let all run through obnoxious expansion chambers. The sound of that bike, at full song, would crack concrete. Rear tires lasted weeks….
    So lucky to be alive with these memories.

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  26. racer99

    Brother-in-law (novice rider) bought one of these back in the day and he refused to ride it after it tried to bite him a couple of times. I rode it a couple of times just because I hated looking at it sitting there unused. First ride I came out of a stop sign and turned left and opened the throttle, nothing much happened so I opened it some more, still nothing so a little more and HOLY S**T the front end came off the ground in the middle of the turn. How I didn’t end up in the bushes I’ll never know. Wicked fast bike when pointed in a straight line and a noise that was worth the price of admission but the “Widow Maker” title is well earned.

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  27. mtshootist1

    Had a buddy when I was in college, he bought one of these 500s, he was a bar owner down in Manhattan KS, big guy, needed to be, If I remember correctly think that within six months he had gone through three sets of pistons, and two sets of cylinders, that thing would pull wheelies without even thinking about it. There is a reason they are rare now. I never cared much for Kaws. I was riding a 52 pan back then that I bought out of the front yard of a guy for 400 bucks.

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  28. JeffAuthor

    Wow, guys, awesome memories! I asked my uncle about these – he’s a motorcycle dude who grew up on these 70s machines – and he echoes your sentiments. I spotted this video and holy crap, what a difference 6K makes: https://www.youtube.com/watch?v=ALJtkogKY-Q

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    • racer99

      Yup, the sound of that thing coming “on the pipes” at 6K still sends a shiver up my spine. It was the only bike I’ve ridden where you had to make a concerted effort just to hang on.

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  29. Joe Howell

    Had a friend with one, another with a 750, they were quick but handled like crap. Z1 was big improvement in handling but could still pass my buddy’s Z1 on the inside of any curve with my Honda 750 and draft him after he passed me again on a straight only to repeat the process on the next curve. We were immortal then. I went thru a bunch of two stroke Yamaha street bikes over the years and now parked next to my Harley is a hopped up Yamaha Kenny Roberts RZ350 for two stoke thrills :) Introduced in 1984 they would do 0-60 in 4.8 seconds stock. Not bad for only 350cc.

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  30. Blindmarc

    Joe H., you got that right. My over bored Daytona would handle and beat most in a straight line or in a curve….

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  31. Larry Matthias

    My roommate came home one day in 1974 with a Kawasaki H1 500 Mach III. I rode it 2 blocks and said, “I got to have one of these” I’d never owned or ridden a motorcycle at all It was a very interesting bike to have as your first ride! Stop light to stop light the only thing that could beat it was its big brother. I had it 9 months before I woke up in the hospital with a compound fracture of my left tibia/fibula. It took the better part of a year to walk again. 19 years old. Very happy to have survived. What a ride !!!

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