(first posted 4/29/2012. Please note that this article does not pretend to be complete and fully accurate as to the origin and development of the Yamaha 650. A number of comments after the article shed valuable additional light on this bike’s origins and development. ED)
Yamaha introduced their 650 in 1968 as the 1969 XS1. Even though it was widely regarded to be an improved copy of the British 650s, it was not. Across the board, the Japanese motorcycle industry was a hotbed of intrigue. Companies would copy other brands or obtain a license to build bikes developed by others versus doing actual “in house” research and development. Considering the devastation brought about by the second world war, that can be easily understood. The XS1 may have been indirectly a copy but of a bike that most of us never heard of. It certainly had its origins in another Japanese bike. Regardless of its origins, the 650 Yamaha became my favorite street bike. I enjoyed the ride but I also find I enjoy the history. Hope you do as well.
First of all, there was a Japanese copy of a British twin and at least when it started, it was legal. The Kawasaki W650 is the copy of the BSA A500. It was a design that was licensed to Meguro by BSA.
Meguro was the largest motorcycle company in Japan at the time. They came through some hard times and in 1960 they were purchased by Kawasaki. Somewhere along the way the 500 was increased to 650 and the bike became the W650. It was produced until the early seventies, then dropped. It appeared again briefly in 2000. It is still being sold in two sizes in other countries. I believe the Kawasaki below is a later model.
The 650 Yamaha is certainly a copy but not of a British twin. One theory of the genesis of the Yamaha 650 is that it was inspired by a Horex. They were bought out by Daimler Benz in 1960 and ceased production of motorcycles.
If thta’s even true, the Horex design did not go straight from Horex to Yamaha, nor did it go unchanged. A Japanese firm named Hosk appeared to get divine inspiration after an intense study of the Horex bikes. They developed and built a 500cc twin that was essentially the only Japanese bike that that could keep up with the British twins of the day.
Hosk was sold in about the same era as Meguro. It was bought out by a company named Showa which we are told was not the same Showa that makes shock absorbers today. Showa was bought by Yamaha. The same engineers that designed the top of the line 500 transformed it into a 650. After languishing for almost a decade it was released again. This time it was the Yamaha XS1.
Your starving teacher was transferred to Panama in August 1972. As usual there was a sailor who was hurting for money. He had foolishly purchased a 1972 XS2 and now had little money left for adult beverages or female companionship. At the time I had money so I purchased his bike for a sum that was too low to repeat without blushing.
People had liked the British twins for years. They were narrow which allowed for a lot of maneuverability, they were light weight, and they were the natural next step for someone who felt they were ready to move up from the 350 or 450 size.
This bike had a single overhead cam. That made the engine slightly taller than the OHV twins of the day. It also had a shorter stroke and these two factors allowed it to rev forever. The ’69-71 model years had front drum brakes. Period articles indicate that my 1972 was the first XS with disc brakes. It was fitted with a single front disc that did the job very well.
The ’69-71 models were kick-start only. That was something you could live with since it normally started with one or two kicks. The 72 model had an electric start and an automatic compression release. Literature suggests that ’72 and ’73 both had the compression release and in ’74 the starter was upgraded. Memory tells me that was needed.
The pistons rose and fell together. This made for an exhaust sound that was smooth and regular. It also made for a higher level of vibration and the engine came without counterbalancing. 180 degree cranks are available through the aftermarket. The sales pitch is that they increase performance and reduce vibrations.
The crankcase was split horizontally which is something the Brits did not seem to understand. That allowed the engine to be practically leak free. In fact, I lived in an apartment where I was able to roll the bike in my front door. I would have had a hard time keeping a BSA or Triumph in my carpeted living room. In the middle of the model run Yamaha dropped the XS designation. The same bike became the TX650 to provide conformity. They also had 500cc and 750cc four stroke twins with the TX designation but actually different designs. The XS designation resumed when those bikes were dropped.
Kenny Roberts was a road racing legend in his own time. In the seventies it was necessary to compete in both road racing and off road events if you wanted to be competitive. The Harley XR750 owned the flat tracks and still pretty much does. The Roberts team upsized the 650 to 750 and campaigned with it. The picture is of Roberts teammate Don Castro with the factory ride. Finding pictures of Roberts on the 650 is difficult because everyone wants to associate him with the TZ750 in a circle track frame that he rode later. The TZ750 would probably have killed a lesser man. The AMA declared it illegal. The 650 team appears to have existed from 71-75 and kept Roberts in the running for the AMA#1 tag.
This bike was very maneuverable due to its narrow width and responsive engine. Many of the same crowd that made the Honda 350 the best selling bike of its time moved to the Yamaha. Many of them became choppers.
Nobody has ever accused the tuning fork people of being unintelligent. Because of the interest in Choppers they developed the XS650 special.
By the time the line ended (1983 in the United States and 1985 in Canada and the UK) the special was all you could buy. This 1980 Yamaha represents the stereotypical look.
Today the most common format for this bike is the circle track, cafe racer or brat bike rebuilds. However, as you can see, it’s been everything. The bike began as an excellent example of technology. The Hosk 500 was capable of keeping up with anyone. The XS1 had the misfortune of being released in the middle of a flurry of technology that included the BSA/triumph triples, the Honda 750, and the MK1 Kawasaki. It represents milking a design for all it’s worth but it does not represent any real time at the front of the pack. Had it been released when Yamaha obtained it, it certainly could have been a hot rod. However, Yamaha already had one that was less expensive to make and already a legend. As a dependable, agreeable, and easy to ride middleweight it had few peers and at least one fan.
Hope you enjoyed the ride.
Lee, thanks for this great piece on a bike I’ve always admired. I wasn’t aware about the connection back to the German Horex; I would have never guessed that. I just assumed what probably most folks did, that the XS650 was a clean-sheet design inspired by the British twins.
Keep the bike histories coming!
Indeed Paul, the first vertical parallel twin was made by Horex in 1932 a number of years before Triumph made one.
I well remember these bikes British bikes were king in my youth but the Yamaha proved a parralell twin could be built without external oiling something the British cant do. I never knew of the German heretage and always thought these were a copy of british twins. Amazing stay awake and learn something every day
Nice history and keep it up. Even though I have a motorcycle endorsement on my license I know nothing of their history other than what I’ve read here and how after WWII motorcycle and scooter production became more of a world wide phenomenon. Good to know my Chinese scooter that is a copy of a Japanese design follows in a grand tradition.
Nice history but Wrong ! The xs-650 /XS1 was built beginning late 69 for the 1970 model year. Not built for 1969
Good catch Mike. I was stationed in Atsugi, Japan when the Yamaha 650 hit the ground…..as a 1970. Could be bought then for $800.00 bucks or 288,000 yen !!!!!! The Kawasaki W650’s were also $800.00. A year earlier, the 750 Honda was being sold for $1000.00 American green backs !!!
Nice history, not too many people know anything about the Horex connection. Most everybody assumes it was just the Japanese wanting to outdo the Triumph 650. Which they did when it came to engine, but definitely did NOT when it came to chassis (typical of the Japanese back then). Due to the chassis shortcomings, a 650 or 750 Bonneville would leave the XS-1 in the curves on any back road running.
Gotta toss in with a few corrections, however:
1. The BSA would be a A50 (actually A50R Royal Star, the red one you’ve got pictured is either a ’66 or ’67, the front brake is the giveaway), not an A500. I had one for about ten years, and despite it looking exactly like the A65 Thunderbolt and Lightning, it wasn’t anywhere near their category. The Royal Star was a big, fancy commuter bike with all of 22hp, while the 650’s were double that and could run with the 650 Triumphs. To it’s credit, the Royal Star is a wonderful example of that old maxim, “Its more fun to ride a slow bike fast, than a fast bike slow.” And the A50 was the only BSA with an engine that wouldn’t self-destruct under hard running.
2. The 2000 (or so) Kawasaki W650 has nothing to do with the 60’s W1 and W2 (that’s what they were called at the time) except being a homage to the original bike. The W650 is a single overhead cam with a shaft drive like the old Norton Manxes and other British designs. It was a nice bike, but unfortunately it was followed a year later by the Triumph Bonneville (same relationship to the old T120 and T140 Meriden bikes), which absolutely crushed it in the marketplace.
3. Yamaha starters of the period: don’t get me started. The original electric starter for those bikes came from the TX500 (vertical twin, DOHC, four valves per cylinder – the first production bike with that configuration . . . . . . . and an OHV Triumph Daytona 500 would eat its lunch anytime). It was underspecced for that job, as I found out on my ’74 XS500. It was then put in the XS650 (previously known as the XS-1 in kick start form). Then it ended up in the original 750 Virago, and, I believe, the 920 and 1000 Viragos. At which point it was completely out of it’s element. I found that out buying a used ’81 750 Virago in 1987, and had the starter die on it within 48 hours even though the bike only had 2000 miles on it. And Yamaha replaced the starter for free. No questions asked. On a six year old used bike.
4. The British knew all about horizontally split crankcases and their oil tight superiority. However, to build an engine that way would have meant replacing all the pre-WWII machinery in their factories with modern equipment. Which meant spending money on upgrading their factories. Which management was unwilling to do. So they kept making, essentially, 1939-1949 engines until the bitter end. This is point #1 about why the British motorcycle industry failed.
5. For those with an interesting in early Japanese motorcycles, I cannot recommend highly enough “Pictorial History of Japanese Motorcycles” by Cornelis Vanderheuvel. Not sure if it’s still in print. It written from a Dutch point of view, but seeing that the Dutch were getting motorcycles in the same order as the US (at least in the big coastal cities), it’s a fascinating look at what came over and in what order.
And most people don’t realize it, but the order in which the US and Europe got Japanese motorcyles was:
Lilac (aka Marusho)
Kawasaki (aka American Eagle)
Yeah, it should have been the Japanese Six, not Japanese Four./
Thanks guys. Syke, thanks for the additional history. With reference to the Yamaha starters, I just figured they were disposable. On the XS650 the first one that worked, IMO was the 74. I just always kicked my yamaha’s to start them.
Ref the Kawasaki 650. I do not believe that there are any parts that interchange. I think it is a completely new bike. The original bike was designed by meguro who my sources said was the largest japanese bike company at the time. I think the 2000 model was a clean sheet exercise. In fact, one of it’s variations is 800cc.
The picture that I enclosed of the Kaw 650 had been labeled a 1960. I felt it was one of the more modern models because of the engine appearance. In fact, the original model was not unit construction. The sources I found said that they are now all called W650, so I did.
I am impressed with your knowledge of the british bikes. Keep reading. I am researching one right now that I hope to publish in a Sunday or two. I love it when someone is interested enough to put in their $.02, although yours was worth a lot more than that. To me anyway.
I’ve been living, eating and sleeping British bikes since the late 1970’s, and have a pretty good reference library here in the office. Plus, whatever I haven’t figured out for myself, somebody in the Virginia British Motorcycle Club has figured it out for me.
That W1/W2 (I believe the difference was whether or not it had single or dual carbs, to confuse things further there was also a W3 in Japan only) has an interesting tank badge. The shape matches the first badge that Kawasaki used up thru the 1967 model year. But it’s also the same shape that the American Eagle badges used (I’ve see one of those bikes, and that’s from a Daytona in the mid 90’s).
As to the date on that bike, 1960 is impossible because Meihatsu and Meguro didn’t join to form Kawasaki until 1963 (both companies were owned by Kawasaki Heavy Industries). The first W1’s were supposedly exported in 1965. Not that I’d know for certain, Johnstown, PA didn’t see a Kawasaki until the old Indian/Triumph dealer took on the line in mid 1968 with the 250 and 350 two stroke twins. Six months later the 500cc Mach III appeared. He never had the 650 twins in stock because the Triumph were selling well, and nobody thought that a Japanese 650 was better than a British one.
I didn’t set out to talk much about the Kawasaki. The main point was that it was the copy of the BSA twin and if you reread the article I think you will find that I was satisfactorily vague. You basically have your act together which does not surprise me. Tonight I did a little searching including your source: Cornelius Vandenheuvel.
He says the BSA that was copied was the A7. He does not mention a license, however, wikipedia certainly does. He further states that the Meguro engine was a step up on the BSA. Especially when the BSA went to 650. The BSA suffered from poor oiling then according to Vandenheuvel. Meguro went with a smaller flywheel and needle bearings which decreased the flex and certainly made the oil supply more than adequate.
When the Meguro was selling like hotcakes it was a 500. Meguro became affiliated with Kawasaki in 1960. I expect the bike labeled as a 1960 Kawasaki W1 was , in fact, a 500cc Meguro K1. The second article indicates that Meguro became affiliated with Kawasaki in 1960 and had disappeared by 1963. The 650 was imported in 65. The articles hint that the increase in displacement may have been 1963. Ask Paul if you can do an article focusing on this bike. You certainly have the knowledge, background, and interest. I would like reading something with less vague information.
I have learned not to fight for the reputation of google images. You caught the one on the BSA and actually Paul pointed out another one before the article was published. I had already rejected several but they are still the only/best game in town and I think I have no choice but to keep using them. I would appreciate it if you would continue to view them with a jaundiced eye and keep me honest.
I sure enjoyed writing the article and I’m glad you enjoyed reading them. I’m doing something different for the next article. I’m writing about a bike that I have never owned or ridden. Keep your eyes open.
What an interesting surprise! As a a teenager, there were loads of XS650s around but the 650 Special was ubiquitous. They were absolutely everywhere in the era of the cheap Yen. Even more common was the tiny 400 Special. Many of my school friends started on 400 Specials and then graduated to the 650.
Me, on the other hand, I had to be different (and still have to…) so at the tender age of 17 I talked my parents into signing for a 1975 Honda CB550F SuperSport. The bike was well used when I got it but all the Good Stuff was there: a Kerker 4 into 1 header, K&N filter and the correct jetting to make it all work. It even had Koni shocks and Avon tires. The thing went like snot (for the time) and the boys with the 650 Specials took an immediate hate to me for having the fastest bike in grade 11. Even after I abused it for two years it was even further abused after I traded up! I sold it to a friend who rode the bag off of it and I saw it bombing around for several years after even that. It was an amazingly well built machine and never once failed me.
Where I lived, the bikes that were most common were:
and of course the Yamaha XS650 special
Re: purchase of the Horex name with the intent of bringing out a bike.
Am I the only one who’s absolutely sick and tired of all these prototype new bikes being brought out carrying the old classic name on the tank? Could somebody please just let Norton die? Contrary to all the prototypes and announced-for-sale-but-never-made-it-into-production bikes, the last real Norton was the rotary which died when the Shenstone plant was closed down in 1992. And it was so chronically underfunded, I’m amazed they were ever able to race the Isle of Man.
By the way, that Norton was actually a BSA. It became a Norton due to the BSA/Triumph bankruptcy turning the company into Norton-Villiers-Triumph.
And the constant attempts to redo Indian also grind me badly, although I’ve got an admiration for the Gilroy, CA attempt which actually put Indian back into production for a number of years until the venture capitalists decided they weren’t making enough on their investment and they pulled out.
There should be a law that if you bring out a new motorcycle, you have to put a new (as in never on a tank before) name on it.
+1 to that. How many times must we be subjected to the zombified corpse of Indian staggering from the grave to sell Tshirts?
I wish there were more standard bikes available like what’s in the first couple of pics. The crotch rockets are damned uncomfortable to ride long distance, the cruisers scrape the ground going into the curves, yet that’s pretty much all that I see out there in the 2012 models from the Big 4.
And, unfortunately, when the manufacturers do bring out something resembling a ‘standard motorcycle’ it invariably doesn’t sell. The standard motorcycle is right up there with the rear-drive, manual transmission, (diesel powered?) station wagon. The bloggers holy grail that they don’t buy on the rare occasion it’s available.
Right now, these is one standard motorcycle out there readily available. But it isn’t Japanese. It’s the Triumph Bonneville.
Couldn’t agree more with you and Syke. I think if you like to play, a hooligan bike is your best bet. That’s where someone takes the fairing off a bike, fits the handlebars and the seat that you like and go with it. Of course, there is always ebay and craigs list. Baruth on the other site just scored an old CB550. Time will tell how that turns out and the seller frequently thinks they are made from gold.
They are the manual, diesel, wagon. There have been attempts by manufacturers to build retro but they don’t seem to last long because of sales.
With a fused back and right wrist I am pretty much stuck with watching and it’s more fun than you would think. There is a derelict XS650 (actually an XS2) in my yard that I keep threatening to rebuild. It’s much easier to threaten than to do it.
My son was given one of these, back when he was in high school… biggest problem: finding parts, and finding someone who could work on a Yamaha 650! (we were living in a small logging out in the middle of nowhere). We found a nice parts bike, and used it to fix up his bike… later, he sold it to another kid… interesting bike, but it didn’t have the “character” of a Brit bike.
Owned my first XS650 in 1974 and have owned at least 25 more through the years.
The model’s continued popularity rests with, parts availability; a 15 year production run, (MikesXS, craigslist and eBay). Ease of maintenance; (only 2 carbs, screw and nut valve adjustment, chain drive, air cooled. And ideal size, Big enough to be a “real motorcycle” and small enough to be easy to handle at low speed. It fits how most motorcycles are really used; for around the local area transportation and enjoyment with an occasional passenger. The XS650 is a hobby and back yard business for me. I have owned at least one of every year and model (well no 74, yet) and many “customs”. I am pleased that interest in an inexpensive old motorcycle gets so many out in their garages getting their hands dirty learning and “inventing”. An art that is becoming harder to practice on modern equipment.
I don’t know if it’s just me but I don’t see much resemblance beetwen the Horex
and the Hosk other than they’re both twins with OHC.Especialy since the one is a unit engine and the other has separate gearbox.The Hosk looks every bit a British copy
(minus the OHC)while theHorex is 100% teutonic(minus the parallel twin configuration).
As for the XS its looks are Triumph.It even fires every 360 degrees just likes the Brits.
Of course the engine has that OHC that makes all the difference,but this is how Japan was doing it.Find the best European design,copy it ,improve it and the next year
bring out a new model and improve it some more.
That’s how they did it.Not plain copying and this is something the Chinese don’t do.
They don’t improve the breed and I don’t believe they are going to produce better bikes
or cars.But this is a different story.
BTW I remember reading in “The Classic Motorcycle” ages ago that the Norton rotary
had nothing to do with the BSA wankel that was found when the old BSA factory was beeing cleared out and which had a lot to do with the Wankel 2000 from Sachs.I’ll try to find the magazine.
Some companys that”time forgot”do make regular motorcycles.Like Enfield for instance
or how about the Ural?(keep a few tools with you just in case…).Or check out the
Moto Guzzi v7 special which by the way has a De Tomaso conection if you look deep enough.
Hi mate, there are few factual errors in your blog and a strange type of apologetic slant to the Japanese. What’s that about? The british borrowed heavily from German designs too after the 2nd world war, no country seems immune from stealing ideas from other (defeated) nations technology. The Russians stole from Germany also, but the Japanese just followed what everyone else did. The BSA batams are copies of german machinery as are the A65 and A50 unit constructions designs except poor interpretations. As for the (w650?) Kawasaki 650 w1-2 they were developed from the a bike made by Meguro under license from BSA. The K models. The final version of W models was a 624cc capacity, and this was arrived at through incremental increases in capacity from 500 until almost all vibrations were eliminated. The XS 650 were not a copy of the Horex. You should have a look at a company called HOSK which developed a single over-head cam shaft 500 twin. This company was bought out by Yamaha, and the rest as they say is history.
i bought a new xs650d in ’77, i still ride it almost daily. great bike. i had owned several hot 2 strokes including rd350, yamaha 305, suzuki hustler 250 etc also a honda 350.. all great bikes but i sold them…but i’m not selling the 650- after 37 years? the xs is a keeper.
Ok, so the xs is not a Triumph. No kidding. I busted my first set of knuckles rebuilding a ’69 Tiger in my parent’s basement and learned and kept going on a series of Triumphs.
The Yamaha was thought of as a bad imposter at the time by us “purists” but I have to admit they didn’t leak (as much) and for the most part were a far more reliable machine.
Not as exciting in terms of power or handling but a decent enough slug.
Now before anybody gets crazy let me tell you that I actually owned a ’72 xs and sold it when I moved off Vancouver Island. A couple of months ago I picked up the same year and colour xs and I’m now in the process of a semi-restoration project (Meaning that as the motor is low miles and good compression, I’m not going to do it “crank up”.
I’m pleasantly surprised at how easy and cheap the parts for it are and what an easy bike to work on it is.
No, I don’t expect that it will blow off my buddy’s “73 Triumph Bonny but that’s not the point. I’ve got much faster bikes in the stable for that. It’s just a good old bike that is a relaxed sunday putt for a mellow afternoon and I’m old enough to be OK with that.
Thanks for listening to my 2 cents
Big Bay Motors, ON.
THE TRUE STORY OF THE YAMAHA XS650
I read a lot of crap on the Internet and on Facebook about Horex and Hosk being the predecessors of the Yamaha XS650.
Every now and then you see the same story and some people believe that nonsense: “It’s on the Internet or on Facebook , so it must be true”.
Belowe you can read the real story about the development of the Yamaha XS650 and the relationship with the Toyota 2000 GT Sportscar.
Thanks to Ludy Beumer for the info.
The following story was written for the Vintage Japanese Motorcycle Club Journal after some, partly incorrect facts were published about this bike, which is becoming (rightfully) more popular now everywhere. Later-on the Dutch XS650 Club (750 members), published it as well.
“True Story of the Yamaha XS650 series”
In Europe the first model seen in some quantity was the XS1F. The Netherlands received the first batch in May 1971. Prior to this a few of the now famous green XS1’s were shipped to Holland, Germany, Switzerland and Austria, for evaluation purposes.
The information hereunder was compiled for me by my Japanese colleague and friend “Dottore” S. Iwasa, who was chassis development engineer for the Toyota cars mentioned later on and who started working for Yamaha in 1959. An old friend of his in Japan sent us the information.
1) Summary of production.
The XS650, the largest 4-stroke motorcycle ever made by Yamaha, was launched during the Tokyo Motor show in October 1969 and was commercialized in March 1970. Production ceased in the spring of 1980, bringing the total production to nearly 300.000 units.
Engine 4-stroke, OHC, Parallel twin, displacement 653 ccm. Transmission 5 speed gearbox, chain final drive. Etc.
3) Objective of the development
The 650 XS1 was the first 4 stroke engine motorcycle ever developed by Yamaha and also the first large displacement engine. Prior to this one the largest engine was the YR-1 Yamaha 2-stroke twin.
In 1965 Honda launched the CB450, which created the gateway to the big motorcycle category for the Japanese manufacturers.
In the U.S. market, where pollution problems were already under discussion, a cleaner motorcycle was preferred and on the other hand 2-stroke motorcycles trailing blue smoke were not getting well accepted. But more important was that market surveys showed an increasing trend towards bigger motorcycles. The target for Yamaha therefore was clear:
* Light weight and high performance
* Easy handling at level of Yamaha’s 350 cc
* For future high engine output SOHC will be better than OHV
* Transferring technology of Toyota 2000 GT engine (designed by Yamaha) to this motorcycle engine
4) Project team
First Engineering group: General Manager Mr. Daisuke Tanaka, Mr. K. Morinaga (who later became the originator of the 5-valve system , Deltabox and other technology of the mid 80’s Yamaha’s and who sadly passed away) and Mr. H. Sakuma.
Engine development: Chief S. Izumizawa, K. Igarashi, M. Arai.
Chassis development: Chief Y. Hironaka, M. Nakano.
Testing: K. Tuchiya, K. Yamaji
5) Process of the development
At the early stage also a 650 cc 2 stroke twin was considered next to the 4 stroke twin. But the 2 stroke was banned because of the unfavorable exhaust note. The project was officially commenced in August 1967. The first pre-prototype was a 650 cc engine installed in the R1 (350 cc) chassis and as target bike “Triumph” was chosen from between Triumph, BSA and Norton for further styling reference. Therefore the feeling of maneuverability and easy handling were developed based upon Triumph. The first prototype was built during the Spring of 1968. Until the end of 1969 a 2nd, 3rd, 4th and 5th prototype were built and 2.500 design modifications sheets were issued!
In the Autumn of 1969 most of the technical problems were solved and the machine was ready for production.
6) Development on the technical side
The basic dimensions for the bore + stroke were taken directly from the Toyota 2000 GT sports car (75x75x6=1998 cc), which was designed and developed by Yamaha on the request of Toyota Motor Co and built by Yamaha between May 1967 > October 1970. 337 Automobiles were built in the Yamaha Iwata Factory, from which 115 were exported. The stroke was just shortened by 1 mm, giving 75x74x2=654 cc. The design of the valve train was the first experience for Yamaha motorcycle engineers, therefore the technology was transferred from the Automobile Division in Yamaha. Although the cam arrangement was changed from DOHC (2000 GT) to SOHC, the diameter of the valves, valve angle, valve stem dimension were taken over completely. For example the valve retainer is the same part as on the 2000GT. (Note: If you are travelling in the Netherlands you can visit the Nationaal Automobile Museum in Wassenaar (near Den Haag (The Hague)), which is owned by the Dutch Toyota Importer, and you can see the only 2000GT’s in Europe and furthermore the Toyota “7” racing car, which was totally developed by Yamaha, and which has world’s first twin turbo charged 5 liter V-8 racing engine).
The difference between the automobile engine and the motorcycle engine was the rpm at max. power, so some parts had to be changed to tougher material and also finally the valve lift was changed from 6.5 mm to 8.0 mm for higher output. The cam profile of the 2000GT was calculated in and by Toyota, so Yamaha could not use it. Yamaha developed their own calculation system for these polydyne cams. Please consider that at that time Yamaha did not have a computer, so the IBM computer from Yamaha Musical Instruments Co. was used during the night!
As for the camshaft Yamaha had no experience with a one piece crankshaft for a 4 stroke engine therefore the same press-fit crankshaft type with identical cylinder pitch as for the YR-1 was used. But a 360 degree crank instead of the 180 degree one was used because of vibration. And where the YR-1 had a labyrinth seal between the crank halves, the XS carries the sprocket for the SOHC. The crankcase were designed also horizontal-split with cast-iron inserts for the bearings, 3 roller and a ball bearing on the right hand side. Lubrication system was wet sump type. Because of the deep crankcases, only the clutch was dipped in the oil. So the function was similar to dry sump.
The pistons were simply 2000GT pistons made of Lo-Ex material. At the beginning the cylinder head had very compact cooling fins, but these grew during development. The transmission parts layout was taken from the YR-1, like clutch, gears, etc. As for the performance, the prototype engine gave only 20 HP. By re-working the cams by hand during the following months we got 42 HP. Finally we reached 53 HP. Oil leakage was the biggest problem in the early stages of the development, but this was fortunately cured later.
P.S. I do hope it is clear now that the ancestor of the XS1 is not the Horex, (even Mr. S. Honda looked more to NSU than to Horex), but a combination of James Bonds’ Toyota 2000 GT and Yamaha’s own YR-1! Also Hosk did not appear at all in the scenario as some people did think. Some of these rumors arose most probably as Yamaha took over several other motorcycle companies during the early days, like Kitagawa Motor Co, Showa Works Ltd. Hosk was already absorbed by Showa Works Ltd. in 1959. Logically engineers from these companies continued their careers with Yamaha and brought their experience with them. This also happened in the German, British and Italian motorcycle industry….
Ludy E. Beumer,
Ex-Yamaha Motor Europe N.V.
Back in 1982 I bought my first (only?) motorcycle, a 650 Yamaha. I briefly considered the XS650, but really favorable reviews, and a cheap yen, led me to the 4 cylinder, dual front disc braked, XJ650.
Not sure which I would buy today as a used bike, but scanning CLs around the country as well as E-bay shows a MUCH wider selection of XS650s. It doesn’t help that very few of us went for 4 cylinders instead of 2….the XJ650 lasted only 1 year.
I owned an XS2 in ’75-76. It vibrated heavily, the mirrors were useless over 60mph and passengers complained that they could not keep their feet on the footpegs due to the vibes. The steering geometry was weird, it just fell into corners at low speed and scared the hell out of friends who rode it. The front forks were the same skinny things fitted to the 350 2 stroke twin and flexed badly under braking and the unbraced swingarm pivot flexed when you wound the power on. You had to ride it like a sidecar outfit, brake to go in one direction and twist the throttle to corner the other way. I learnt a lot from that bike and really enjoyed it. I bought a new Triumph 750 in ’78 and did 40,000 trouble free miles with no oil leaks other than some misting around the pushrod tubes. The Triumph taught me just what good handling is, just as the XS2 taught me what bad handling was.
It is very rare for people to the origins of the xs 650 correct. I believe this because a vertical rwin was first produced in England. The intial template for the xs was a 1950’s german verticle twin it turns out called a horex imperator, which had a chain driven over head cam, something the British were unable to engineer until the 1990’s. Horex and a japanese company were involved in technology sharing.The Horex in question had tappet adjustment covers in the same location on head/rocker cover as the later xs650.
Now, l want to iron out the issue with the kawasaki W1 or as it was originally know the Meguro K1. This 500cc twin was indeed based on the BSA A7, but in term of its engineering was far superior, make no mistake. Theengineering tolerances were so good they never leaked oil. Now when kawasaki got their hands on the K1 they decided to increase capacity, but they did this incrementaly starting off with a larger bore, the increasing it untill they had produced a capacity that did not vibrate as much, 624cc and where they stopped. All of the W model range up until 1975 had the same bullet proof 624cc motor, that could give any 654cc A10 a toweling, mainly because they came with twin mikuni carbs, not a single Amal monobloc. Indeed the the Wseries had a longer production run than either the A10 or A7.
Thanks for sharing my shot of Don Castro on the #11 Yamaha factory XS at the Terre Haute Half-Mile AMA Grand National flat track race from September ’74, great times!
Bought my new 76 xs650 for $1450. Took epic cross country rides. 25000 completely trouble fee miles. Tires and chain and sprockets is all. As fast as a 69 GTO from stop light to stoplight. Mine vibrated just right. Mirrors were not useless, don’t know who told you that.
Perfect motorcycle. Short seat height, light, low end power. Handling was just fine. Would run 100 mph all day.
First bike was a Yamaha 250 Big Bear Scrambler and lasted well until a car with boat trailer pulled across the road in front of me and then stopped for opposing traffic. I survived but bike didn’t fair as well. Great learning bike as it doubled for off road teaching.
Replaced it with the topic bike, a 1970 first year edition of the XS650. Loved this bike. Vibration and handling was never a problem and really enjoyed the years riding it. No leaks and zero mechanical problems with day to day maintenance in my garage. A comment on the bike that stuck out the most was from two observers in Wasaga Beach one night. They were trying to figure out what I was riding and when I stopped we had an interesting chat. Their comment that stuck out was that it looked and sounded somewhat like a Triumph but knew it wasn’t because the lights were working, “definitely not Lukas electrics”.
Ultimately replaced this machine with first gen ‘72 Kawasaki Z1 900. Loved that bike too but a girlfriend at the time didn’t like the ride as much and it turned out she like the vibration of the 650. Hmmm? Seems taste is very much in the eye of the beholder.
Everyone complains about the vibration, I prefer to say Purr! I believe this is coming from Either 40 year old memories, or the fact the speed limit was 55 mph, right in the worse part of the max rpm for vibration on the 650 twins. If you take them up to 70-75 which is closer to todays highway and some rural speed limits, and the vibration levels off nicely. Also they make custom foot peg covers and handle bar grips for the geriatric, or or overly sensitive
I had 100 honda, then twin 100 Yamaha (10 years old on the farm) I grew up riding on gravel roads so they are like coming home to me now, Next a 350 Honda 4 BEAUTIFUL Ruby res paint but a dog, A 550 4, smooth but doggie in the city stop and go. Then I bought my first XS650 and fell in love! I have had well over a dozen, a couple leak oil out of the rear sprocket seal. They oiled the chain nicely, also the back of your shirt, or worse your passenger. I had a Suzuki 3 cyl “Water Buffalo” It moved and when you hit the power band at about 6000 rpm it about jerked your teeth out but it had a fairing and it cycled the exhaust (2 CYL) in my face…. Tested a Bonneville 650 nice but at only 8000 miles the SHITTY ELECTRONICS left me beside the road, on my test drive! I walked the mile back to the owners house and guess why he was selling it.. I’ll take solid reliability over a few extra MPH in the 1/4 mile and Headlights blinkers randomly working or dead bikes any day. I got 60k on one 650, still ran but used oil, bottom end was still solid as a rock. Just sold a tired 75 for $1800.00, and bought an 81 Special with electronic ignition, all stock, and running with 9000 miles on it, (LUCKY, after I bought it was offered $1600.00 for it) plus has a good (for now) charging system for $600.00
Sorry Lucas Electronics…Not Morris on the Triumph! I’m suffering from the Lucas Blues right now with my 70’s MGB!
I had one of these, an XS650 special, actually a couple of different ones, it was a great bike, handled well, maneuverable in the city, comfortable enough for shortish trips. But… The Vibration! Like people say it liked to rev, but with the revs came the tingling and with the tingling came numbness of the extremities, which you had to watch out for on a long ride.
Also it wasn’t quite as oil-tight as people say, in particular the seal for the shift lever shaft on the left-hand-side tended to leak.
Yamaha starters – it HAD an electric starter, but it wasn’t something you wanted to rely on, really. The kickstarter was not only a neat feature to impress the ladies (or maybe not impress them as they note that you are perhaps more of a Neanderthal than they thought) but the saving grace of that bike, because it meant you were always going to be able to get home. That starter was terrible, and speaking of experience with a 920 Virago and an XS750 triple, Yamaha didn’t seem to understand how to design a reliable electric starter until sometime around 1985.
I had a friend that had one of these in the early seventies. When he would let it idle on the centerstand in his garage it would literally walk all over the garage from the vibration.
I’m inclined to think that the 1980 Yamaha 650 Special that you have pictured might actually be a late run 1979 (or I suppose it could be a very early run 1980), as all of the 650 Specials I owned from a 1980 to a couple of 1983 parts bikes I picked up all featured an aluminum grab bar for the passenger seat, and had the brake light tucked up under the rear of the seat. The first motorcycle I ever owned was a 1972 XS-2 that I picked up for a measly $20US it had been sitting in a barn for close to 30 years by the time I got hold of it and much of the wiring and rubber needed to be repaired/replaced, I was able to cheat a bit with the air filters as I found a lawnmower air filter that fit perfectly and only had to have cardboard glued to one side in order for it to work as the oem ones did. I had to rebuild from caliper and master cylinder though, and finding parts wasn’t easy, I finally found what I needed from MikesXS in Florida (not sure if he is still around but he specialized in parts for the Yamaha XS series and their predecessors like the TX series and the XS-1 & 2. My 1972 XS-2 did not have an automatic compression release but rather it was a manual cable operated design with an integrated starter switch that engaged when you pulled the lever. Someone had replaced the stock exhaust with a set of turnouts that in some ways made it look more like a bigger cruiser model, but had a tendency to hit the pavement on sharp turns, so I got a set of taper tip slipons from a mail order company that fit nicely and actually cleared the pavement when I took sharp turns. After that I got my hands on a 1980 650 Special in fairly nice shape for $75US that had had the kick starter lever welded on by someone (fortunately by then I had already picked up a few other 650 Specials for parts that had good engines and just ended up swapping in one of those engines so I could still be able to service the clutch later one if I needed to). My 1980 had the same rear disc brake setup as the one in your picture which I learned was not the default configuration and was a special model unto itself the XS-650SG while the other models came with rear drum brakes. In addition to the 650 Special Yamaha also produced a Heritage Special edition some of which came with wire spoke wheels, and some came with cast aluminum wheels.
thoughts on the 650 twin. a friend who had owned one for several years said ” the best brittish bike ever made is a yamaha 650″. maybe so… i`ve been told they require less maintainance( i`m speaking of engine-trans) and are far easier to work on than a triumph or b.s.a. the japanese were quite tardy in developing chassis that were worthy of their (usually) great engines.( i won`t go into the tx 750 or the suzuki madura here). i always heard that the 650 was inferior to the brit twins on handling. depending on how and why one rides, handling and braking can rate from ” not very” to ” extremely” important on the priority list. i only rode a xs 650 once, a couple of miles on a country road. it was relatively light and had sufficient power, at least for certain types of roads. then i slowed to turn it around. i could easily stand up on the pegs and turn my 500 lb.
z1 or later gs1000 around using both lanes of a 2-lane country road, not so the probably-around-415-lb yamaha. it was, i think, one of those ” midnight specials”, low seat, slow-steering, raked-out front end. what a great way to ruin a good bike- put a good engine in a cosmetically “cool-looking” chassis. i never understood that apparently rather successfull marketing niche. it`s like they were making motorcycles for people who didn`t really ride. speaking of handling, as a kid in the early 70s i always attended the dirttrack races in the astrodome each spring, starting event of the a.m.a. season. i`ll never forget kenny roberts on his yamaha 650- based flattracker, taking the inside line in a power slide,leaning to the inside over the laid-down hay bales, with the bike laid over to the max, left- side case scraping the soft track and leaving a 30 ft track. twice!
Very interesting comments & history about the Yamaha xs650’s. Theres good, bad. & ugly info.! I have a ’75 & considering a ’70– which is, imo, the best looking– along with the ’71 models as well! Nice ones aren’t cheap anymore but nothing is & you only live once! Great article & site!