1970 Yamaha R 5 Technical Analysis & Specification Breakdown
At the heart of the 1970 Yamaha R 5 naked motorcycle, Yamaha utilizes a 347 cc (21.2 cu in) air-cooled twin, two-stroke layout. In factory specification, peak output is rated at 35 HP (25.5 kW) at 7,800 rpm while maximum torque reaches 37.9 Nm (28 lb-ft), transferring power to the rear wheel through a 5-speed gearbox and chain final drive. With a specific output of 100.9 HP per liter, the engine character is reflecting a performance-oriented street tune that balances strong mid-range pull with an energetic top-end rush.
On the scales, the R 5 measures 148 kg (326 lbs) wet (curb), translating to a power-to-weight ratio of 0.24 HP/kg (4.23 kg per horsepower). Rider ergonomics and chassis geometry center around a 790 mm (31.1 in) seat height — offering a neutral standover height that accommodates most average-inseam riders without sacrificing cornering clearance, combined with a 1,341 mm (52.8 in) wheelbase engineered for quick, flickable steering geometry. The 12-liter (3.2 US gal) fuel tank paired with a rated consumption of 6.7 L/100 km provides an estimated theoretical range of roughly 179 km (111 miles) between fill-ups, while factory top speed is listed at 160 km/h (99 mph).
Within MotoLibrary's Yamaha archive, this model family spans 2 indexed model years from 1970 to 1971, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
100.9 HP/L
Power-to-Weight
0.24 HP/kg (4.23 kg/HP)
Theoretical Range
~179 km (111 mi)
Engine
Displacement347.0 ccm (21.17 cubic inches)
Engine TypeTwin, two-stroke
Engine DetailsTwin, two-stroke
Power35.0 HP (25.5 kW)) @ 7800 RPM
Torque37.9 Nm (3.9 kgf-m or 28.0 ft.lbs)
Compression6.9:1
Bore x Stroke64.0 x 54.0 mm (2.5 x 2.1 inches)
Fuel SystemCarburettor. 2 Mikuni VM28 SC
Fuel ControlPort control
IgnitionBattery, dual coils, breaker points
LubricationOil injection
CoolingAir
Transmission
Gearbox5-speed
Final DriveChain (final drive)
ClutchMulti-plate, wet
Performance
Top Speed160.0 km/h (99.4 mph)
Fuel Consumption6.70 litres/100 km (14.9 km/l or 35.11 mpg)
Greenhouse Gases155.4 CO2 g/km. (CO2 - Carbon dioxide emission)
Chassis
Frame TypeDuplex cradle frame
Front SuspensionTelescopic fork
Rear SuspensionSwingarm
Wheelbase1341 mm (52.8 inches)
Ground Clearance180 mm (7.1 inches)
Wheels & Brakes
Front Tyre3.00-18
Rear Tyre3.50-18
Front BrakesExpanding brake (drum brake)
Rear BrakesExpanding brake
Dimensions & Weight
Dry Weight146.0 kg (321.9 pounds)
Weight incl.148.0 kg (326.3 pounds)
Power/Weight0.2397 HP/kg
Seat Height790 mm (31.1 inches) If adjustable, lowest setting.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Torque
Torque is useful for judging real-world pull, especially for touring, commuting and loaded riding.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.