"Kawasaki Ninja 250R"

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.

"Nomenclature"

Motorcycle Kawasaki Ninja 250R Blue Series

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 (EX250-E/F/G/H) were already being marketed as members of the Ninja family of sportbikes, 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 Ninja 250R's particular ergonomics, chassis design, and engine placement have resulted in a motorcycle that straddles the standard and sport classes. The Ninja's riding posture also falls somewhere between standard and sport. The bike is capable of running the quarter mile in 15.58 s @ 81.98 mph (131.93 km/h),[3] although it had been 1 s faster in the prior generation, while providing the amenities of more utilitarian motorcycles, including bungee hooks for transporting cargo and space for a second passenger.

"Description and features"

Kawasaki_250R Motorbike Motorsport

The latest model, the EX250-J or fourth generation, brought the Ninja's first major update in many years. Appearance upgrades included an increase in wheel size to 17&inch, and completely redesigned fairings which give the motorcycle a sleeker, more modern appearance than the boxier earlier generations.

"First generation (1983–1984)"
EX250-C - Also known 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.

"Second generation (1986–1987)"
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.

Kawasaki_Ninja_250R Motorsport

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 32 mm (1.3 in), the cylinder compression ratio was increased from 12.0:1 to 12.4:1, and ignition timing advance was increased. Reviewers were pleased to report 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

The third generation of production of the Ninja 250 encompassed three models:

• EX250-F - The most widespread EX250 variant, the E model was completely revamped and sold as the F model between 1988 and 2007 in the U.S. Canada received the model between 1988 and 1999, and it was available elsewhere as the GPX-250R as early as 1987.
• EX250-G - Sold only in its home market of Japan, this version was known as the GPX-250R-II. It featured dual front brakes and a wider wheel and tire (110/80-16). All other parts were identical to the -F model. It was sold after 1988.
• EX250-H - This model came to Canada as the Ninja 250R between 2000 and 2002, after which it received a new name: ZZR-250, in line with the -H model's name elsewhere in the world, where it had existed since 1992. This motorcycle has few parts in common with the -F model, though it shares the same engine, albeit with different casings. It sports a lateral aluminum frame, a different fairing (designed to make it look sportier), larger 17" wheels, an adjustable rear shock absorber, adjustable brake and clutch levers, a smaller drive sprocket, computer-controlled timing advance, and a revised electrical system. 

"Fourth generation (since 2008)"
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.

Motorsport Kawasaki-Ninja-ZX-10R-red motorbike

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, where the motorcycle spends most of its time. The redesign of the engine resulted in improvements in engine response at low RPM, and making the bike smoother and "much easier to ride." Though the previous generation Ninja 250 had a peak power of 1 horsepower (0.75 kW) more, or peak engine power of 5 horsepower (3.7 kW) more according to official Kawasaki specifications, according to testing by Motorcycle Consumer News,  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 beefed up, 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 (22 lb) increase in wet weight over its predecessors.
With the arrival of the EX250-J, manufacturing continues to be located in Thailand

"Motorsports"
Since the introduction of the model in 1986, the Ninja 250 has been often used as a starting class bike in club racing around the world.[citation needed] The American Federation of Motorcyclists (AFM) in California has been especially involved with 250 Production racing since the bike was released,  including the since faded Honda VTR250.

In 2007, the last year of the third generation EX250, the Ninja 250 of Hambone Racing won the overall the Central Motorcycle Roadracing Association (CMRA) Mini Endurance Championship. EX250s placed 1st, 2nd, 3rd, 5th, 6th, 8th and 9th in the 2010 CMRA Mini Endurance Championship.