![]() | |
Manufacturer | Yamaha |
---|---|
Production | 1974–present |
Successor | Yamaha YZ450F |
Class | Motocross |
Engine | 249 cc (15.2 cu in) water-cooled reed-valve two-stroke single |
Bore / stroke |
|
Transmission | 5-speed |
Suspension | Monoshock, 12.8 inches travel |
Brakes | Double disc |
Tires | Front: 80/100-21-51M Rear: 110/90-19-62M |
Wheelbase | 1,470 mm (57.8 in) |
Dimensions | L: 2,200 mm (85 in) W: 830 mm (32.5 in) H: 1,300 mm (51.2 in) |
Seat height | 990 mm (39.1 in) |
Weight | 103 kg (227 lb) (US 2014 model) (wet) |
Fuel capacity | 7.9 L; 1.7 imp gal (2.1 US gal) |
Related | Yamaha YZ450F |
The Yamaha YZ250 is a two-stroke motocross race bike made by Yamaha. The model was launched in 1974, and has been regularly updated and is still in production with new releases every year.
The original YZ250 of 1974 used an air-cooled 250cc two-stroke engine of 70 mm bore and a 64 mm stroke, which was improved semi-annually. The air-cooled motor was replaced in 1982 with a 249 cc liquid-cooled two-stroke reed-valved engine with a mechanical, rather than servo-driven, YPVS exhaust valve for a wider spread of power. Although other makes of contemporaneous motocross engines featured theoretically superior crankcase reed-valves, the YZ250 still has the reed-block integral to the cylinder.
The bore on the water-cooled engine was reduced to 68 mm and the stroke was increased to 68 mm producing a displacement of 247 cc. In 1999, the bore was further reduced to 66.4 mm and the stroke lengthened to 72 mm producing a displacement of 249 cc. The longer stroke engine resulted in a lower redline, slightly less top end power and greatly improved torque at lower RPM. The engine produces a peak 47 horsepower (35 kW) at 8,800 rpm and 30.6 foot-pounds force (41.5 N⋅m) of torque at 7,500 rpm, with a 9,000 rpm redline. [1]
A large range of after-market tuning parts are available, owing to the bike's design being fundamentally unchanged since 1999 and the sheer numbers sold over the last fifty years.
According to US Dirt Bike magazine, it is the last 250 two-stroke from Japan.
On its introduction in 1974, the YZ250 used a single backbone steel frame with a twin-shock swingarm. The following year, reflecting the factory racer Hakan Andersson's factory racer, the swingarm became a monoshock unit, initially made of steel, then aluminum from 1978. The swingarm rear suspension system featured more than 12" of travel, while the telescopic inverted front forks had 11.8 inches (300 mm) of travel. [2] In the 2005 model year, the YZ250 gained a new frame made from aluminum that reduced the dry weight to approximately 212 lb (96 kg). All YZ250s feature front and rear hydraulic disc brakes. The 2014 US model had wet weight of 227 lbs. [3]
![]() |
1999 | First year of the current engine |
2002 | First year of the current frame geometry and bodywork |
2003 | Exhaust port raised about 0.5 mm and higher compression head for USA model. |
2005 | Aluminium frame |
2006 | KYB SSS forks |
2007 | Pro Taper 1-1/8 handlebars |
2008 | Smaller fork lugs and shorter lower tubes. Brake calipers also reduced in size + wave rotors. |
2011 | No more US model: Bigger silencer and a neutral switch for sound checks. Low compression head. |
2015 | New body work (compatible with 2002–2014 bikes). Smaller fork tubes (at top clamp) from the four-stroke. |
Motocross is a form of off-road motorcycle racing held on enclosed off-road circuits. The sport evolved from motorcycle trials competitions held in the United Kingdom.
The Honda XR series is a range of four-stroke off-road motorcycles that were designed in Japan but assembled all over the world.
The BMW M50 is a straight-6 DOHC petrol engine which was produced from 1990 to 1996. It was released in the E34 520i and 525i, to replace the M20 engine.
The B-series are a family of inline four-cylinder DOHC automotive engines introduced by Honda in 1988. Sold concurrently with the D-series which were primarily SOHC engines designed for more economical applications, the B-series were a performance option featuring dual overhead cams along with the first application of Honda's VTEC system, high-pressure die cast aluminum block, cast-in quadruple-Siamese iron liners.
The VK engine is a V8 piston engine from Nissan. It is an aluminum DOHC 4-valve design.
The Yamaha XV1600A is a cruiser-style motorcycle. It is also called the Yamaha Road Star or in Europe the Yamaha Wild Star. It was produced from 1999 through model year 2014 when the Roadstar model line was discontinued. The 1999-2003 models were the same 1602 cc naturally aspirated engines. In 2004 they changed the displacement to 1,670 cc. There were also a few design changes in 2004, including new tubeless aluminum wheels, a skinnier drive belt, and different engine casing color. The Road Star has a sleeker, sportier brother called the Yamaha Road Star Warrior that has a fuel-injected 1,700 cc engine and an all-aluminum chassis. The Road Star remained unchanged until 2008 when electronic fuel injection was introduced to the bike. There were variations of the Road Star with different trim and equipment packages. The Road Star was available with a Silverado trim package which included studded saddle bags, a back rest, studded driver and passenger seats, and a cruiser-style windscreen. The Silverado package changed names to the Midnight package with blacked out engine etc. For a few years, the Road Star was also available in an "S" package, which meant more chrome pieces for the buyer.
The J-series is Honda's fourth production V6 engine family introduced in 1996, after the C-series, which consisted of three dissimilar versions. The J-series engine was designed in the United States by Honda engineers. It is built at Honda's Anna, Ohio, and Lincoln, Alabama, engine plants.
The Yamaha SRX is a motorcycle that was manufactured from 1985 to 1997 by the Yamaha Motor Company. Not to be confused with the Yamaha Sidewinder SRX, which is a snowmobile.
The Honda F-Series engine was considered Honda's "big block" SOHC inline four, though lower production DOHC versions of the F-series were built. It features a solid iron or aluminum open deck cast iron sleeved block and aluminum/magnesium cylinder head.
The Yamaha XZ550 'Vision' is a 550 cc V-twin, shaft-driven sport touring motorcycle produced by Yamaha in 1982-1983. It was powered by a 4 stroke 70° liquid cooled 4 valve DOHC engine, and featured a trailing front axle and monoshock single swingarm rear. With a range of innovative technology for its class, nimble handling, and bold styling, it was widely celebrated by the motorcycle press on its introduction as a bike ahead of its time.
The Honda R engine is an inline-four engine launched in 2006 for the Honda Civic (non-Si). It is fuel injected, has an aluminum-alloy cylinder block and cylinder head, is a SOHC 16-valve design and utilizes Honda's i-VTEC system. The R series engine has a compression ratio of 10.5:1, features a "drive by wire" throttle system which is computer controlled to reduce pumping losses and create a smooth torque curve.
The Suzuki GSX-R750 is a sports motorcycle made by Suzuki since 1984. It was introduced at the Cologne Motorcycle Show in October 1984 as a motorcycle of the GSX-R series for the 1985 model year.
The Suzuki GSX-R1000 is a supersport motorcycle made by Suzuki. It was introduced in 2001 to replace the GSX-R1100 and is powered by a liquid-cooled 999 cc (61.0 cu in) inline four-cylinder, four-stroke engine although originally 988 cc (60.3 cu in) from 2001 to 2004.
The Yamaha DT200 is a dual-purpose motorcycle manufactured during the 1980s, 1990s, and continues into the 2000s (decade) by the Yamaha Motor Company. Though never imported into the US, the rest of the world, including Canada, received some of these models. The DT200LC began production in 1983bc. It also was very similar to the DT125LC. This model continued production until 1988.Then, in 1989 a totally new model was introduced, DT200R (3ET), as well as a similar DT125R. In Canada, the DT125LC/R was never imported.
The Yamaha WR450F is an off-road motorcycle made by Yamaha Motor Company. It currently has a 450 cc (27 cu in) liquid-cooled single-cylinder engine. First offered in 1998 at 400cc, it shared many components and design concepts with the YZ400F motocross model. It is basically the racing YZ450F detuned slightly for more controllable power, with a headlight and lighting coil, softer suspension, a kickstand, lower noise specifications, larger radiators and lower emissions. The WR in the name indicates a wide-ratio gear box common to most enduro or trail bikes and stands in contrast to the close-ratio gearbox essential to a motocross racer. Over the years the WR has benefited from the advances made in the YZ motocross version gaining displacement and advancements such as an aluminum frame and improved suspension. Over much of its life the weight of the WR450F has remained fairly constant ranging from 244 to 249 pounds dry weight.
The Yamaha YZ125 is a motocross racing motorcycle with a two-stroke 124.9 cc (7.62 cu in) displacement single-cylinder engine made by Yamaha since 1974. It is available to the public. For the first two years it was made with dual rear shocks, then changing to a monoshock. The YZ125 has been ridden to five AMA National Motocross Championships, and multiple AMA Regional Supercross Championships.
The Yamaha YZ450F is a four-stroke racing motocross bike built by Yamaha Motor Corporation. It was the successor to the previous YZ426F which was discontinued in 2003. It is credited by Cycle World and Dirt Rider magazines as the bike that started the four-stroke dirt bike revolution. The 2006 YZ250F and YZ450F were the first production motorcycles equipped with titanium suspension springs.
The Honda NS400R is a street-legal two-stroke sports bike produced by Honda between 1985 and 1987. Adapted from Honda's NS500 Grand Prix motorcycle ridden by "Fast" Freddie Spencer, the NS400R is the company's largest-displacement street-legal two-stroke road bike.
The Nissan VRH engine family consists of several racing engines built by Nissan Motor Company beginning in the late 1980s. All VRH engines are in a V8 configuration, with either natural aspiration or forced induction. Some VRH engines are loosely based on Nissan's production V8 engine blocks, including the VH and VK engines, while others were designed from the ground up for racing and share no components with production blocks.
Yamaha IT175 belongs to the 'International Trial' family of motorcycles, produced during the 1970s and 1980s. The machine is derived from the Yamaha YZ range of competition motocross bikes with modifications for use in competition enduro, hare and hounds and trail riding.