Super Bike Survivor: 1973 Kawasaki Mach III
Talk about a brut of a performer on two wheels. The Kawasaki H1, also known as the 500 CC “Mach III” was a two-stroke quarter-mile killer – what many would refer to as a pocket rocket. Common in everywhere America for years, a Mach III is rarely encountered anymore so finding this example, described as a survivor by its seller, is a nice find. This 1973 example is located in Vernon-Rockville, Connecticut and is available, here on eBay for a current bid of $8,600 with 70 bids tendered so far.
Introduced in 1969, the Mach III was notable for its three-cylinder engine configuration, its 13.0-second straight line, quarter-mile acceleration capability, and its affordable $999 price. In later years it was joined by the smaller Mach II (350 CC) and the very stout Mach IV (750 CC). In production through 1975, the Mach III, along with its smaller and larger brothers, is a seldomly encountered motorcycle anymore.
The seller claims that this California bike has not been refinished and was stored, indoors for 30+ years. No doubt about it, it looks great. I recall these being finished in green but finding them with white tanks and side covers was common too. The seller refers to it as being “extremely rare” – as stated, maybe finding one today in this shape, but there is nothing inherently rare about a Mach III. An owner that I knew back in the ’70s said that as fast as they were, the engine wasn’t particularly durable and they had a tendency to wear out quickly. Of course, some of that may be due to the way they were thrashed. They were also tagged for quirky handling, mostly in sweeping turn maneuvers.
And that thrashing was courtesy of a 60 HP, 500 CC (499 really) three-cylinder, two-stroke engine working through a five-speed manual transmission. The seller states, “The engine kicks over and has good compression” though the ignition key is reportedly missing. This bike also comes with the old “ran when parked” claim which was apparently eight years ago. It is suggested that the fuel tank will need a “light rinse“, varnish from stale fuel perhaps?
It seems fitting that this Kawasaki is from California, being that it has a two-stroke engine and you can’t sell as much as a weed wacker there anymore; California, no more, I guess. The mileage is listed as 26K and I can’t say with any authority whether that’s considered reasonable or not for a bike of this nature – but please feel free to comment on that matter. If you’re interested in knowing more, here’s a video that you can review. Referred to as a “Widowmaker” that’s enough for me to give it a hard pass, but how about you, any thrill-seekers out there?
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Comments
Sure there will be one person put these down but just look at the price and bids. Another one I sold to soon……..
When these show up here, they tend to generate the same comments about the acceleration, the iffy handling, and that unmistakable sound. All valid.
Growing up, I always wanted to live a year in NYC. Didn’t.
And I always wanted to own a Mach III. Same.
Here we go again, I thought the 750 was the Widowmaker, but Jim is right. All these bikes could fit that name, just about everyone that had any connection to these, pretty much tells the same story, like 370 sez. To be clear, with the expansion chambers, which is like headers for a 2 cycle, probably adds a bit more hp, but will suffer drivability problems, if any to begin with. The chambers add a distinctive growl,( open, no baffles, downright intense) and probably helps cool the center cylinder, prone to running hot, and usual demise, center cylinder stuck. If this is the actual mileage, which I highly doubt, the vibrations of these machines killed even the best Asian gauges, it’s a lot of miles for this type of bike, 1/2 mile at a time. All I can say having ridden one, even the most macho biker will get a mighty surprise above 6 grand,,,Buy this,,if you dare. BTW, “Widowmaker” is a bit much, ALL of these motorcycles with wicked acceleration have that potential. I’ve driven some fast machines, and still typing. Common sense is the rule here.
Agreed Howard. These were a death trap. The best bike of the era was prob a 500cc Honda. Smooth running, reliable, handled well. More power then you would ever need. Why do people always have to push the limits on, well, pretty much anything? I guess we are about the same age, and realize that life is precious and limited. Use with caution.
G-d daxit, this logging in bull plop MID COMMENT, is getting old,,,already pixxed off at 3am,,ugh, where was I? Cabin fever, big time. I think, Fred, the biggest thing was, at the time, these were just about the fastest thing one could drive, and not many bikes that you may have driven previously, could prepare you for this kind of acceleration. Wicked acceleration aside, these, if driven sanely, which was hard to do, they weren’t bad bikes really. Everyday low speed cruising fouled plugs, and clouds of smoke became offensive, besides, by then, a Z1 was much more civilized and just as fast. I think later, Suzuki had the hottest stick with the GS1000.
Funny – I’ve owned them since the 70’s and I’m 65 yrs old – they didn’t
KILL me………..
The expansion chambers add power higher in the rev range, but take away power in the low range..so you have a “light switch”power band..nothing..nothing..then reach for the sky! These pipes are meant for racing and make the bike a pain to ride regularly.
The expansion chambers dont by definition add power just in the high rpm band. They add power for whatever rpm range they are designed for. It is possible to design a set that would increase low end power or whenever. In reality the most common were in fact designed for high mid range increases. They work by tuning the pipe so sonic and pressure waves would be reflected and arrive at the exhaust port just in time to increase cylinder filling.
With the aftermarket exhaust,air filters,seat cover and not running seems like a lot of 💰.I’ve had several and they were fun.I think they are more desirable to someone who never rode one:-)
I am a former triple owner (400). Had a look at the ebay pics, this bike has been left out in the weather for a long time. Rusted shock tubes, original paint that doesn’t match the tank to the side covers, hasn’t run forever, “odd” look to the odometer (but as Howard said, maybe just vibration?), seat is wrong. Its a 20 footer….
Seems like a great restoration project, but at the (likely) price of a runner. Love that it showed up here though – fantastic bikes….
cheers,
BT
Kawasaki let’s the good times roll so get aboard get away and let the good times roll
Had one in high school scary fast great for impressing girls with wheelies and burn outs mine was all black and had expansion chambers it was LOUD fun for around town zips but could only stand it for 6 months and traded it in on a new triumph tiger 750
I have owned five of these screamers and an even faster 750. I knew they would be worth money, but suddenly are worth more than CB 750 Hondas as evidenced by the BAT sale week of a purple 73 model for $40,000. I sold my last 500 in 2012 for $4,000. It had only 5,000 actual never in rain or sat outside miles with perfect orig seat and exhaust. Should have waited.
Never had one, but I did admire them as also the 750’s at the drag strips. These are not for the inexperience ridders, so be careful. They may not be as fast as todays bikes, but were quicker, I believe. As with most 2 strokes, they didn’t last long before a rebuild. Nice find!!!!
That’s a lot of miles for a 2 stroke bike that averaged about 20 mph. Sold one just like it in 1980 for $500. Maybe should have kept it😳
Well, being the speedo is front wheel driven, it may have many more miles,,,seeing the front wheel rarely touched the pavement,,
I remember my Brother’s 1976 KZ 1000. I got it up to 120mph and the front end started to shimmy so much I thought I was a goner. I stopped and got some fresh underwear and went back to riding
2 smoke 🚬 🚬
all the Japanese had these – may B 300 – 750 (may B even a 900cc) triples, 2 stroke just edging into the super bike era. I gave mine away as too buzzy (ever ride a chain saw?) & stuck w/my ’78 KZ750B (2 cyl) since the day (traded in/out others, but kept the KZ as it’s the most maintainence free I’ve ever had).
Till the comment above (“…rust…gashes…”) I would have said “Not” to the survivor – as a 10 footer it looks fine
To Fred’s comment re 500cc Honda’s; I just became the 4th owner of an all-original 1976 Honda 550 Supersport. Oddly, I am also the second owner, having bought it back 12 years and 500 miles later from my pal!
It is one sweet, smooth ride. No vices whatsoever, and beuatiful to look at.
So, would I buy a KH 500? Damn right I would! You haven’t lived until you’ve heard these at WOT. And I rode my KH400 for years – it was dead reliable.
cheers,
BT
Still have my 72 H1B that I bought in 73. Not quite original. Eldest son found out the hard way about it coming “alive” above 6000 rpm. Endo-ed it. Thankfully he was OK but the bike got banged up a bit. Above 100 mph I had to pull forward and sit on the tank to keep the wheel on the ground. Looking back on it now I wonder how/why I did some of the crap I did on that thing but I was young… and arguably stupid when on it. It was boggy at low RPMs but hold on tight above 6K!
No keys and not running? Too dear.
Green paint, tho’ – an’ spannies!
The white ones were H1s rather than KHs, weren’t they? I know that the KH can also be an H1-E (for example), but the early ones didn’t have a KH designation.
The early 500 triples (‘69-‘70) were H1s and had white fiberglass tanks. Those had really unpredictable and “exciting” powerbands and flexy frames and swing arms. Later models had steel tanks of various colors and graphics, and the last ones (around 74-75) were KH500s with smoother power bands, stronger frames front disc brakes, etc. Those were still quick, but much more rideable than the first ones.
I had a 72 750. Bill Wirges expansion chambers along with the rejecting, front sprocket down one tooth gearing it from 3:36 to 3:73, bored but didn’t know what to. Absolutely the fastest, brutalist ride I ever owned and I owned a lot of muscle cars. I had a low 13 second 396 Chevelle at the time and it would nearly half track it or so it seemed. No matter who you put in the car or on the bike, beat it like it stole something. Absolutely good for nothing else. Couldn’t see out the mirrors above 60, couldn’t keep your feet on the pegs above 80, license plate wouldn’t stay on it. Simply a wide open, infinite wheelie popping, tire burning, vibrating, 1/4 mile blaster. Finally melted the center piston and locked up on me at 125 MPH while out running a state trooper.
Rejecting might be better than rejetting. I built and rode one back in the day. I wasn’t married at the time, but got religion on a sweeper at speed with a tunnel entrance. The solid concrete corner of the tunnel came THAT close…Never got over it and sold it soon after. Great sound contributed to a huge speed perception.
Let me correct you Jim O’Donnell it’s Crotch Rocket not pocket
I was trying to be polite.
JO
I guess I don’t get out much cause even tho I had the Yamahas RD and RZ 2 strokes I never seen or knew Kawasaki had a 2 stroke street bike..i think I was so into.the Yamaha’s I had tunnel vision. I eventually put a RD 400 engine Tweaked every way possible, jetted shaved reed ported polished racing exp.pipe ..into the lighter RZ 350 frame cause you just get addicted speed .the bike was about the most fun you could have accelerating but it was also trying to kill me so after one too many close calls and sliding down the road on my back far enough I sold it and boxes of spare parts to some other guy with a death wish.
I can imagine these triple 500s and 750s must be just ridiculously quick. I’d love to watch somebody driving one wide open. It won’t be me.. I hate the hospital lol
Kirk, the Yamahas had their “BAD” bikes also. I rode the 350 2 stroke that had the oil injection system, instead of mixing the fuel & oil. I’m thankful I flipped the bike one day on me and broke my left leg, because I’m sure I would of killed myself one day on it. Also rode the 360 enduro (dirt bike), that at the time was a bit much for me also.
Still riding a Yamaha RD 350, 1974. Just about the easiest bike to ride ever. Lightweight, small frontal area, decent handling for its time. What makes it “BAD”????
cheers,
BT
A guy at a job I had in the late 80’s had one of these. His tank was repainted blue and wasn’t as nice as this. I wonder if he even has it.
I owned an H1 back in the middle/late ’70s. It was set up much like this one – chambers, re-shaped ports, re-jetted carbs, etc. It was loud, unpredictable and ill-handling (mainly because it consistently burned the tread on the rear tire flat…). That said, I usually got off of it scared silly and grinning like a fool…
The “Widow maker” nickname came from the very narrow and abrupt power range which came on very high on the Tach. When you reached that RPM suddenly the front wheel was in the air. Back in the day, I was on a bike just like this one, rounding a curve leaned way over on a dark night going way faster than prudent when something knocked my foot off the peg !?! Next morning going back to work there it was, a giant Porcupine I had hit with my foot !!! If I had been 6 inches closer to the center line that night ??!?!?
BT, “BAD” as “hold on to your hat”, it’s quick. I would do 90 in two short blocks.
Me “BAD” Terry – I didn’t get it!
bt
A friend of mine road raced one of these in the ’70s as a privateer(sic), then got sponsored. Put that motor in a street frame. Wheelies at 140 in 4th on throttle. Scary and exciting. I don’t do that anymore
The ‘ Two stroke tuners handbook’ that was out about the same time as these bikes was a must have when tweaking your 2 stroke
Original brochure for my dads 71 500 mach 3. The picture with the better info is too big to attach here sorry. Someday we’ll get it running again and I’ll see what these are all about. A friend of mine is really into the Honda 250R quads from the mid 80’s. He had a couple that were pretty built, I remember those having an interesting power band too. Just the way of the 2 stroke i guess. Atleast this one seems a little better than the one with the ape hangers from a couple weeks ago.
I love reading the comments about owners experiences. I’ve owned a few H1’s over the years, most non runners except for the ’72 orange with front disc brake I paid $600 for and yard rode. Sold it later for $1,000. No problem as I made a profit. The best triple IMHO was the 1972 S2 350 w/45 HP out of the box. It was red and had a drum front brake and was far better looking than the 2nd model year, ’73 w/disc front brake. I really miss my two ’72s. Oh well, I have my RDs that are just as quick and handle much better.
There are geniuses in every country but in my mind this fellow, chap, bloke or whatever the Brit’s call them may take the cake. How about a home built Kawasaki H1 with 2 extra cylinders? Or a V-twin made from a radial airplane engine? He even built a Z1 900 V8 engine in his home shop. All running and ridable bikes. If you’re curious:
https://www.youtube.com/c/AllenMillyard/videos
I had the 1974 750 – 2 cycle with Denco pipes. When I met my future wife and she was scared of riding it so I sold it. I should of got rid of her, Since I divorced her years later. I miss that bike. It was like a tealk in color.
I always liked the Suzuki GT750 triple, little quieter with the liquid cooling, my bike is a 1977 and it runs perfect year after year, nice ride, slow compared to today’s 750’s thats for sure, going up in value every year, i remember when you could hardley give one away.
I had 2 of the triple 750 Suzukis. The 75 was the first year with upgraded horsepower, and if you went down 2 teeth on the front sprocket it became much quicker with no penalty in mileage or drivability.