subject: The Development Of Kawasaki Ninja 250r Motorcycle [print this page] The Kawasaki Ninja 250R (previous generations had market-specific names) is a motorcycle originally introduced by Kawasaki in 1983. As the marque's entry-level sport bike, the motorcycle has undergone few changes throughout its quarter-century lifetime, having received only two substantial redesigns. The fourth-generation model is marketed as the Ninja 250R in all markets. The motorcycle is also referred to by its platform designation, EX250, to which a generational suffix is attached. In the United States, previous generations of the bike were already being marketed as members of the Ninja family of sport bikes, while outside of the U.S. the bike was known variously as the ZZR-250, ZX-250, or as the GPX-250R. One of the earliest generations, the EX250-C, was given the name GPZ-250.
The first generation was produced between 1983 and 1984, and known by the production number EX250-C. It was sold as the GPZ-250. Sold only in its home market of Japan, this earliest, belt-driven version was first produced in 1983, and shares no commonality with later generations. The bike has 35mm fork tubes. Produced between 1986 and 1987 was the EX250-E. This model was sold as the Ninja 250R in Canada and the U.S. between 1986 and 1987. It was known as the GPZ-250R elsewhere. When originally introduced, it was more costly than the Honda Rebel, and reviewers complained that while the 14,000 rpm redline was nice, the engine was slow to rev. For the 1988 model year, there were both cosmetic changes and changes in engine tuning. While the bore and stroke, and other major engine components, were unchanged, minor tuning adjustments were made. The carburetor diameters were reduced 2 mm to 30 mm (1.2 in), the cylinder compression ratio was increased from 12.0:1 to 12.4:1, ignition timing advance was increased, and the rear sprocket was increased by three teeth to 45. Reviewers reported that this made the engine more free-revving, reaching the high 14,000 redline more quickly, and the tested top speed increased by a few miles per hour. The new, more fully enclosed bodywork was complimented for being stylish, at the time, and easily mistaken for the larger Ninja 750.
In 2008, Kawasaki gave the EX250 its most thorough modernization in many years. The EX250-J model is known as the Ninja 250R worldwide, regardless of market. Parts from the third generation are still found on the -J, but its redesigned exterior panels bring the Ninja's appearance out of the 1990s and into line with late-2000s sportbikes. The engine and drivetrain retain 30% of the -F model's parts, according to Kawasaki. The engine's compression and maximum torque have been lowered to provide better midrange performance. The redesign of the engine resulted in improvements in engine response at low engine speeds, and making the bike smoother and "much easier to ride." Though the previous generation Ninja 250 had a peak power advantage of 1 to 5 hp, the new version's 20 or 30 percent increase in mid-range power allows the bike to pull from 3,000 rpm where previously it had to be revved to 4,000 rpm. The U.S. -J model uses dual carburetors like the -F model, but the European, Brazilian and Thai models have fuel injection. The wheels were increased in size to 17 inches, the front suspension was improved, and the brake rotors were replaced with a larger petal shape. On the carbureted version, a fuel gauge was added in place of the temperature gauge. With the additional and redesigned equipment, the EX250-J suffered a 10 kg increase in wet weight over its predecessors. With the arrival of the EX250-J, manufacturing continues to be located in Thailand. For more info about Kawasaki Motorcycle Fairings and Kawasaki Fairings, please visit our website neverland-motor.com!
