The Yamaha R5 is a motorcycle made by

Yamaha Yamaha may refer to: * Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below). ** Yamaha Music Foundation, an organization estab ...

for production years 1970 (R5), 1971 (R5B) and 1972 (R5C). It was the first iteration of a new generation of horizontally split crankcase two strokes that also included the

RD350 The RD350 is a two-stroke motorcycle produced by Yamaha from 1973 to 1975. It evolved directly from the piston port (pre-reed valve intake tract), front drum-braked, five-speed Yamaha 350 cc "R5". The engine is an air-cooled, parallel twin, s ...

and culminated in the

RD400 The RD400 is a two-stroke air cooled six-speed motorcycle produced by Yamaha from 1976 until 1979. It evolved directly from the Yamaha RD350 The 350 evolved into the RD400C in 1976, the "D" and "E" in '77–'78 and the final model, the white 19 ...

. The engine platform also included the 250cc variants (DS7/

RD250 The Yamaha RD250 is a two-stroke motorcycle produced by Yamaha Motor Corporation is a Japanese multinational manufacturer of motorcycles, marine products such as boats and outboard motors, and other motorized products. The company was e ...

). Two earlier generations of sporting 250cc and larger displacement air-cooled two strokes preceded the R5 dating back to 1959.

History

Yamaha began producing air-cooled "sport tuned" 250cc twin cylinder roadsters in 1959. Development led to increased capacity in 1965 to 305cc (YM1) and in 1967 to 350cc YR1. These are the ancestral predecessors to the 1970 350cc R5 and represent two different generations of engine evolution and design. The 1967 YR1, 1968 YR2 and 1969 R3 (YR3) directly preceded the R5 and were Yamaha's first publicly available 350cc capacity air-cooled, two stroke twins. The R5 was superseded by the 1973-1975 RD350 and 1976-1979 RD400. Several technical changes were made to the RD platform, the most significant of which being the six-speed transmission and reed valve induction. Though different in appearance the R5 basic architecture lived on in the RZ350 (American market) and RD350LC (Euro market). The main difference being the cylinders became

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 non ...

. The engine cases are similar enough that, with modifications, they can be interchanged.

Identification

The two-stroke era

In the early 1970s, a engine was considered large for a two-stroke engine. Two-stroke street motorcycles from Yamaha,

Suzuki is a Japan, Japanese multinational corporation headquartered in Minami-ku, Hamamatsu, Japan. Suzuki manufactures automobiles, motorcycles, All-terrain vehicle, all-terrain vehicles (ATVs), outboard motor, outboard marine engines, wheelchairs ...

and Kawasaki collectively developed a reputation as "giant-killers". Even though four-stroke motorcycle engines (not chassis) were being developed rapidly, during the 1970s, two-strokes were able to best them in straight-line performance at times. Because of the lighter weight of the engine and chassis, two-strokes were typically dominant on curved roads. During the '70s, the two stroke developments were between Kawasaki, Suzuki, and Yamaha. At this time, Soichiro Honda was alive and active in his company. He did not personally like two-strokes, so Honda stayed focused on four-strokes. As the decade went by, Suzuki added displacement, cylinders, and water cooling, culminating in the

GT750 The Suzuki GT750 is a water-cooled three-cylinder two-stroke motorcycle made by Suzuki from 1971 to 1977. It is the first Japanese motorcycle with a liquid-cooled engine. The Society of Automotive Engineers of Japan includes the 1971 Suzuki ...

, a touring bike. Kawasaki added cylinders and displacement, ending with the infamous H2 750 Mach IV. By default, Yamaha became the bantamweight, maxing out with a twin, still air-cooled.

Racing

In the early days of the Yamaha racing team, factory race bikes were not as specialized as they are now. In fact, they were hand-built versions of the production street bikes. Beginning with the basic parts of an R5, the racing TR3 model was built.

References

{{reflist R5 Two-stroke motorcycles Motorcycles powered by straight-twin engines Motorcycles introduced in the 1970s