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 W2SS was made to boost 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.
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 disc 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.