The Suzuki RG250 Gamma was a two-cylinder parallel,

water-cooled Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and no ...

250 cc

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 ...

motorcycle produced by

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 ...

from 1983 to 1987. One of the major features of the RG250 Gamma was its large

power-to-weight ratio Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...

. Able to produce up to 45+ BHP at 8,500 RPM and 38.4 Nm torque at 8,000 RPM, weighing in at roughly 130 kg. The RG250 Gamma was the first

mass-produced Mass production, also known as mass production, series production, series manufacture, or continuous production, is the production of substantial amounts of standardized products in a constant flow, including and especially on assembly lines. ...

motorcycle to have a lightweight aluminum frame and racing type aerodynamic fairing. The Gamma also had a very advanced 'full floater' suspension system for its time, with the first Mk1s having 'anti-dive' front forks (which locked the forks under hard braking to stop them diving). Due to this, the bike was dubbed the first street legal racer. In its five years of production the model underwent three major changes: Mk1 (1983–1984): 45-46 hp and 38 Nm torque. Very first bikes had a single

brake disc A disc brake is a type of brake that uses the calipers to squeeze pairs of pads against a disc (sometimes called a rakerotor) to create friction. There are two basic types of brake pad friction mechanisms: abrasive friction and adherent frictio ...

on the front. Mk2 (1985): Revised front fairings, mudguard and colour scheme and a slightly shorter wheelbase (from 1385 mm to 1360 mm) Mk3 (1986–1987): Introduction of Suzuki's AEC system (Automatic Exhaust Control). This gave the bike a higher (around 49-50+hp) power rating. (AEC system: Same idea as the now standard power valve design, but using a 'butterfly flap' to open and close an addition chamber on the

cylinder head In a piston engine, the cylinder head sits above the cylinders, forming the roof of the combustion chamber. In sidevalve engines the head is a simple plate of metal containing the spark plugs and possibly heat dissipation fins. In more modern ...

(open @ low RPM, closed at higher). This effectively expands the exhaust system at low RPM, to allow the exhaust to be tuned for high RPM. The AEC system opens at around 7500 RPM) Mk4: (1987): There was also a very short-lived Mk4 version created for the Japanese home market, which had larger front discs, thicker tyres and larger diameter front forks. This model was never exported. The RG250 Gamma was replaced by the RGV250 Gamma (V-Twin) in 1988.

References

{{reflist RG250 Gamma Motorcycles introduced in 1983 Two-stroke motorcycles