The Suzuki GT250, also known as the Suzuki Hustler in the US is a ,

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes of the piston, one up and one down, in one revolution of the crankshaft in contrast to a four-stroke engine which re ...

, twin-cylinder motorcycle produced by the Japanese

Suzuki is a Japanese multinational mobility manufacturer headquartered in Hamamatsu, Shizuoka Prefecture, Shizuoka. It manufactures automobiles, motorcycles, all-terrain vehicles (ATVs), outboard motor, outboard marine engines, wheelchairs and a va ...

company between 1971 and 1981. The model was developed from the earlier T250, and was one of the best selling motorcycles in its class. For 1978 the bike was redesigned and marketed as the GT250 X7. The X7 was capable of reaching in favourable conditions. The model range was discontinued in 1981 in favour of Suzuki's

four stroke A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either directi ...

models, and the X7 was developed into the RG250 Gamma.

Technical details

Engine and transmission

The T250's engine was a development of the earlier T20, which had been introduced in 1966. The 180° piston ported two stroke twin was of

unit construction : ''For the vehicle design where the vehicle's skin is used as a load-bearing element, see Monocoque.'' Unit construction is the design of larger motorcycles where the engine and gearbox components share a single casing. This sometimes includes ...

and had alloy

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple ani ...

and alloy

barrels A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids ...

with cast iron liners. Bore and

stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

were and the claimed power output was @ 7,000 rpm. In 1971 the ''Ram Air System'' cooling duct, as used on the GT380 and GT550, was added to the cylinder head. It is debated whether the Ram Air System improved cooling significantly or was a cosmetic addition. In 1976 the engine was revised; the

main bearing A main bearing is a bearing in a piston engine which holds the crankshaft in place and allows it to rotate within the engine block. The number of main bearings per engine varies between engines, often in accordance with the forces produced b ...

s were increased in number from three to four and two extra transfer port added, increasing power to @ 7,500 rpm. The ram air was removed and the fins on the head enlarged to compensate. A new engine was designed for the 1978 X7 model. Whilst retaining the 54 mm bore and stroke, the engine was more compact and weighed less than the GT250C engine. The new engine used Suzuki's dual induction system, first used on its off-road bikes. The system used both piston porting and

reed valve Reed valves are a type of check valve which restrict the flow of fluids to a single direction, opening and closing under changing pressure on each face. Modern versions often consist of flexible metal or composite materials (fiberglass or carbo ...

s, which gave better response through the rev range.

Ignition Ignition may refer to: Science and technology * Firelighting, the human act of creating a fire for warmth, cooking and other uses * Combustion, an exothermic chemical reaction between a fuel and an oxidant * Fusion ignition, the point at which a ...

was by twin coils with

points A point is a small dot or the sharp tip of something. Point or points may refer to: Mathematics * Point (geometry), an entity that has a location in space or on a plane, but has no extent; more generally, an element of some abstract topologica ...

mounted on the end of the

crankshaft A crankshaft is a mechanical component used in a reciprocating engine, piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating Shaft (mechanical engineering), shaft containing one or more crankpins, ...

. Fuel was delivered by twin 26 mm Mikuni

carburettors A carburetor (also spelled carburettor or carburetter) is a device used by a gasoline internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the Ventu ...

, which had restrictive slides to reduce intake noise. The carbs were increased to 28 mm in 1975 and were rubber mounted. The carbs were reduced to 26 mm on the X7 to increase mid-range power. The engine was lubricated by Suzuki's ''CCI'' system. Primary drive was by helical gears to a multi-plate wet clutch. The six speed gearbox received revised second and third gear ratios in 1976.

Chain drive Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles. It is also used in a wide variety of machines besides vehicles. ...

took power to the rear wheel.

Cycle parts

The duplex cradle frame of the T250 was modified for the GT250 with three small top tubes instead of the previous single large tube. Rear suspension was by

swinging arm A swingarm ( or swinging arm), originally known as a swing fork or pivoted fork, is a single or double sided mechanical device which attaches the rear wheel of a motorcycle to its body, allowing it to pivot vertically. The main component of the ...

with twin

shock absorber A shock absorber or damper is a mechanical or hydraulics, hydraulic device designed to absorb and Damping ratio, damp shock (mechanics), shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typic ...

s. At the front

telescopic fork A telescopic fork is a form of motorcycle front suspension whose use is so common that it is virtually universal. The telescopic fork uses fork tubes and sliders which contain the springs and Shock absorber, dampers. The main advantages of the ...

s were used. A new single downtube frame was designed for the X7, which saved over the previous frame. Initially brakes were

drums The drum is a member of the percussion instrument, percussion group of musical instruments. In the Hornbostel–Sachs classification system, it is a membranophones, membranophone. Drums consist of at least one Acoustic membrane, membrane, c ...

front and rear, the front being an effective 2ls item. The front brake was replaced in 1972 with a single

disc Disc or disk may refer to: * Disk (mathematics), a two dimensional shape, the interior of a circle * Disk storage * Optical disc * Floppy disk Music * Disc (band), an American experimental music band * ''Disk'' (album), a 1995 EP by Moby Other ...

, which suffered poor wet weather performance.

Model variants

The first of the GT250 models was introduced to the Japanese home market in 1971 and apart from some cosmetic changes was identical to the T250. The Ram Air System and disc frame brake were added in 1972. In 1973 the model was introduced to export markets.

GT250

Introduced to the Japanese domestic market only in 1971, the model was based on the T250 and had styling similar to the T350.

GT250 II

Still only for the Japanese market, the 1972 GT250 II gained a disc front brake, gaiter on the front forks and Suzuki's Ram Air system.

GT250K/L/M

In 1973 the bike was restyled and released in Europe and America in 1973 as the GT250K. The exhausts were modified to comply with noise and emission regulations which reduced power. It was available in red, candy blue, candy pink or green with a white or silver stripe, outlined in black. The 1974 L and 1975 M models had minor cosmetic changes only.

GT250A/B/C

An updated engine was introduced in 1976 with a 4 bearing

, 2 extra transfer ports and larger carbs which increased power. The Ram Air System was removed. Although the GT250A faster than the previous model, it suffered from lack of power below 4,000 rpm. In the UK the model was heavily advertised with the then 500cc world champion

Barry Sheene Barry Steven Frank Sheene (11 September 1950 – 10 March 2003) was a British professional motorcycle racer and television sports presenter. He competed in Grand Prix motorcycle racing between and , most prominently as a member of the Su ...

heading the campaign. The GT250 became the top selling 250 cc bike, the learner class at the time. The 1977 B and 1978 C models only differed by minor cosmetic changes.

GT250 X7

The bike was redesigned for the 1978 X7 (known as the X7E in Germany and RG250 in Japan). The bike was lighter than the GT250C and more compact. Although producing no more power than previous models, the new engine was more tractable. The lighter and more compact X7 was capable of under favourable conditions. The X7 continued in production until 1981 and formed the basis of the RG250 Gamma.

References

External links

* * * {{Suzuki T & GT series timeline, state=autocollapse GT250 Motorcycles introduced in 1971 Two-stroke motorcycles Motorcycles powered by straight-twin engines