In the 80s of the 20th century, the engine selection for Yamaha sports cars continued to expand, from the 4-cylinder XJ400 to the SR single-cylinder, the V-twin XV to the water-cooled DOHC twin-cylinder XZ400, and even the single-sport SRX400 600...At the same time, after considering whether to build an air-cooled parallel twin engine that played a dominant role in the all-important 250 400 class, whether to make it unnecessary or to find value to survive, Yamaha decided to continue with the traditional model decided to take on the challenge, using technology and design to emphasize the necessity and novelty of its existence.
The XS400 250, released in 1982, inherited the narrow engine width of the XJ series, with a generator mounted at the rear of the cylinder, a diamond-shaped frame without a downtube that made the engine part of the body structure, and a motocross bike with its layout and design that set it apart from the conservative 2-cylinder models of the previous one, employing the Monocross system, which had been Yamaha's strong point since road racing in the '90s.
The engine has a displacement of 399cc, a bore of 69mm and a stroke of 534mm。The air-cooled DOHC has 45ps at 9,500rpm, which is the upper limit of self-adjusting, and the maximum torque is 35kgm 8,000rpm, performance is sufficient. Its construction is unprecedented, with stamped steel plates for the frame and steering head, and a dry weight of just 169 kg. In the same lineage, the American "special", which is in great demand mainly in the United States, was added to the lineup with a similar configuration and design.
The XS250, developed in partnership with the 400, doesn't have as many engine options as the 400cc class, so many users are looking for something in the middle, so the XS250 is attracting attention because of the novelty of the overall configuration.
The color scheme also responds to the user's desire for a more mature sensibility, with simple and fashionable monochrome colors, as well as bright and refreshing casual colors. In 1984, the XS250S with a mini-fairing was added to the lineup.
Since Yamaha also has an RZ250 in the 250cc category, it doesn't have a large market share, but it has been well received by self-identified Yamaha fans because of its obvious differentiation from other manufacturers.
The 249cc engine was reduced from an XS400 to a bore of 56mm and a stroke of 506mm, air-cooled DOHC performance at 33ps at 10,500rpm and maximum torque of 23kgm/9,500rpm。The lightweight body, dry weight 166 kg, moderate stability, comfortable handling, suitable for the majority of riders to ride easily. This design and color image has the same sensibility as the innovative water-cooled DOHC V-twin XZ400, but it didn't become a popular model with the XS400, so it's widely considered to be the unique design of the XS250.
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