Kawasaki W1 to W3

W-650, W1, W2, W2SS, Commander, W2TT, W1S, W1SA, W3


The W123 Story


It all began in England with the BSA A7 A10 parallel twins. (Se picture below.)  Around 1960 a Japanese manufacture, Meguro based their new 500ccm bike the K1 on the BSA A7/A10. For its day, the K1 (picture below) was an advanced design and showcased modern-day manufacturing techniques with its Air-Cooled , 4-stroke, 496cc capacity, 360 degree parallel twin with overhead valves,  all mounted in a double-cradle frame. And  by 1960, Meguro Works entered into a business arrangement with Kawasaki Aircraft Co, Ltd.

In 1963, Meguro Works merged with Kawasaki Aircraft Co, Ltd, forming Kawasaki Motor Sales Co.  Soon to become Kawasaki Motorcycle Co, Ltd. Kawasaki then made some small changes to the Meguro K1 and made the K2. The Kawasaki K2 didn't sell very well so Kawasaki soon decided to do something  "hotter". The W1 was born in October 1965

BSA A10 1959 BSA A10 1959 Meguro K1 1960 Meguro/Kawasaki K2 1965
Note: If anyone have some pictures of the K1 and/or K2, then I would very much like to have a copy :)    
Meguro/Kawasaki K2 1965      

The W1 may look like a copy of the BSA from the early 50's. Especially compeering the engines. A quick look at the engines and you may think they come from the same brand just another years production.

But Kawasaki did a lot of work with the new W1: First of all its not leaking oil. The BSA and even the K1/K2 used two piece con-rods and plain insert type bearings. Kawasaki made a big improvement bye using ball and roller bearings all over and one piece rods and a one-piece pressed crankshaft assembly The lubrication was still dry sump but Kawasaki paid more attention to the ventilation and oil flow to improve reliability. Another important improvement was the oil filter incorporated in the right side cover. The "new" engine was enlarged to 624cc, still only one carburetor was fitted, a Mikuni VM 31mm. The compression was 8.7:1 and maximum power was 50 hp at 6500rpm. Not much, but a lot more then the BSA produced.

All over the W1 was much better then the BSA or K1/K2 bikes.  But the gearbox was not up to the standard f the engine. The gear-change smoothness and precision was far from satisfactory. Anyway this was changed already in 1967, se below.

BSA at the top, Kawasaki under BSA at the top, Kawasaki under

W1 1966-1968: 

 The W1's Instruments  1967 W1 1968 with two tone seat cover 
 1966 W1     1968 with two tone seat cover   1968 with two tone seat cover 
Black 1968 with two tone seat cover       Very nice W1, probably 1967    


The W1 was launched in 1966 as a 650 (624ccm) street bike.  One 31 mm carburetor and 50 hp at 6500 rpm. The bike was quite good-looking with much chrome and a classic look (even then) Testers back then found the handling good with excellent brakes and satisfactory performance. Cycle World measured the bike's top speed to 162.5 kph and the quarter mile in 15.6s with a top speed of 136.7 kph. The colors available was black, candy red and candy blue. The bike is easily recognized by its single carburetor and instruments incorporated in the headlight. The instruments were a one-piece affair placed on top of the headlamp shell like the 250 Samurai. A twin leading front drum brake was used with a single drum unit rear. The indicator flashers were an optional extra.

In 1967 The W1 got the same gearbox improvement as the W2SS (se W2SS below). In 1968 You could have your W1 with a two tone seat cover. Total produced was 3282


W1SS 1967(-?) First version, one carburetor

1967 W1SS   1968W1SS  
       Real nice 1968 W1SS  
The W1 didn't sell as much as Kawasaki had hoped it would. So to boost sales they made a more sportier version., the SS.  Kawasaki  changed the exhaust muffler structure & shape. The exhaust where shorter and so where the front fender. The rear fender stay now incorporated a small grab handle and the saddle vas reshaped. On the side panel there was a nice 650SS sign. Like all W's from 1967 the gear mechanism was improved for more accurate gearing and the front wheel was one inch bigger, now 19inces. Power and performance was the same as for the W1. This is a quite rare W model sins only 251 bikes where made. Note this bike has only one carburetor. SS stands for Street Scrambler 

W2SS 1967-1970

1967 W2SS source: Wikipedia.   1967 W2SS
1968 W2SS Source: Roy Bacon's book 1967 W2SS 1968 W2SS 1968 W2SS
1968 W2SS 1968 W2SS 1968 W2SS 1969 W2SS 1969 W2SS
   1969 W2SS Source: Cycle Chaos     1967 W2SS Ad 
  1968 W2SS       

The W2SS was made to boos sales in the US. The W2SS is much the same as the W1SS except one significant change. It got twin Mikuni 28mm carburetors replacing the original single 31 mm. This resulted in a new cylinder head. The intake valves was upped from 36 to 38 mm and both the intake and exhaust valves was redesigned for better cooling.  The engines compression ratio was up to 9:1 from 8.7:1. Power was up 3 hp to 53hp, this was archived 500 rpm higher in the rev range. (7000rpm). Other changes compared to the W1 was one inc bigger front wheel now 19inc, the exhaust mufflers  and fenders was smaller. Performance was better: Cycle World clocked top speed at 180.2kph and a 14.5s quarter mile at 146.4kph.

Like all other W1, W1SS and W2 etc, the gear box was improved. The earlier model was well known for its lack of smoothness and precision of its transmission. This cause of female and male gears trying to engage each other running at different speed. Resulting in missed shifts and a noisy gear shift. This was totally eliminated from 1967. This cure was a use of the engagement of knobs or dogs, into holes of the corresponding female gear. The female gear had six holes to the males three knobs resulting in a much improved transmission.

In 1969 the chromed gas tank was dropped in favor of a painted one. (at least in the export version) Instruments were separated from the headlight the headlamp was changed as was the headlamp brackets.  The bike was now given a new name, the 'COMMANDER'. Color options were Candy Black, Blue or Red

1969 W2SS Production for export to the United States in 1969 produced 639 units of vehicles.



W1S 1968-1970

All bikes 1968
All bikes 1969
For sure, some very nice bikes here.
The W1S was a W2SS built for the home market with  Japanese specifications. Dry weight was up from 181 to 199kg. Some confusing  model names on these old Kawasaki's. the W1S didn't got the new painted fuel tank for 1969 but kept the chromed tank. Like late W2SS instruments was separated. Hard to find any information about the W1S pleas email me if you can contribute.


The W models in detail.
< >
Both the W1S, W2SS and the W1SS got shorter exhaust pipe and a shorter rear fender
All except the 1969 and newer W2SS and W2TT models kept the classic Kawasaki badge shown in the picture on the right side.
The engine vas basically the same on all models.  The main difference was an engine head with one or two carburetors. W1S with two carb's show here.
Foot brake on  left side of the engine, and the gear selector pedal at right up until they got it right with the W1SA in 1971
Left: W1S logo
Right W1SS logo.
The bike was called W-650 in its home country, Japan.
Separated instruments on the W1S, late model W2SS and the W2TT


W2TT 1968 -1969

  The W2TT 1969 early version. >
1968 W2TT Export version. >
Left 1968 Exhaust system.
Right 1969 Exhaust system.
1969 export version. >
The W2TT was based on the W2SS and was made for the American marked.  The difference was a side mounted and upswept exhaust system.  One version for the Japanese home marked with chromed gas tank. And one for export with painted gas tank. It was produced only in 1968 and 1969. The 1969 model was updated  with new instruments, new paint (blue) and a different exhaust system.  Totally under 650 was produced.


W1SA 1971 - 1972
  New engine covers on both side. On the right a big "W" dominates.
On the left cover  Kawasaki is written with big letters.
Both side covers have a new design with a nice "650" label.   But the most significant change is the new gear selector  mechanism where the gear and brake level have changed side. The gear selector sited on the left side of the engine. Se the details on the pictures.
  The instruments where also updated from the W1S. Speedometer and rev counter have changed side and the instruments look more modern.   New tail light with double reflectors. And the bike got updated drum brakes.  
The blue bike is a 1971 model, the orange one a 1972.
The W1S had a rather big update for 1971, becoming the W1SA. The most significant update was the movement of the shift lever from right to left side of the engine. Same place as all bikes today have. This was done with some nice mechanical levels on both side of the engine (see pictures above). There were new colors, the chrome gas tank was gone and new engine side covers   made the bike stand out from earlier versions. Brakes was updated, up front a bigger more advanced drum brake guarantied stopping power. The rear drum was much the same as before, but painted black. Actually a lot of parts was updated, new instruments, new front and rear lights, new indicators and new rear shocks to mention some. Sill a popular bike in Japan but the engine configuration was  an quite old construction at this time. The W1SA was not exported as the earlier W2SS and TT

W3, 650RS 1973-74

< 1973 models < 1973 & 1974 model
1974 models >

The W3 also called 650 RS was the last of the W series bikes. It was produced between 1973 and 1974. Compared to the W1SA it replace, the RS most significant change was new brakes. Double dishes brakes, same as the brand new Z1, but unlike the much more powerful Z1 the RS had double discs as standard. The new instruments was also borrowed from the Z1. The front fender fasteners had a different design, the tail light fastener was chromed. And the rear drum was not painted black.

After nearly ten years and 26289 bikes the W production ended.    


  The W1 was gone, in 1999 the W650 was born. The W650 and from 2006 the W400 have inherit a lot from the W1-W3 bikes. Take a look at the details and compare them with the W models.  
  2001 W650   2007 W400  
  The 250 Estella, this bike my not remind you as much as the W650  about the W. But take a look at the W3 above and compare the fuel tanks....,  
  2005 Estrella   2002 Estrella  
  Sources: Most information about the W bikes on this site comes from various internet sites like the ones in the section below. And some info from books like "The Kawasaki Story" by Ian Falloon.  
  Cycle Chaos Lots of info about any bike here.  
Hard to find information about all the W bikes
  In Japanese, but relly a good place to find some nice bikes. Tip: Google translate.  
  German site about restoring a W1. Nice pictures.  


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          Last update:   15. desember 2013