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The RD400 is a 399 cc (24.3 cu in) 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 '78–'79 and the final model, the white 1979 RD400F. (The model year for the first RD400, which was sold in the U.S. in the summer of 1975, was 1976.)

Yamaha RD400 DX 1978.jpg
1978 Yamaha 400 DX
ManufacturerYamaha Motor Company
PredecessorYamaha RD350
SuccessorYamaha RD350LC
Yamaha RZ350
Engine399 cc (24.3 cu in), air-cooled, two-stroke, straight twin
Bore / stroke64 mm × 62 mm (2.5 in × 2.4 in)
Compression ratio6.2:1
Top speed106.8 mph (171.9 km/h)[1]
Power44 bhp (33 kW) @ 7,000 rpm[1]
Torque30.3 lb⋅ft (41.1 N⋅m) @ 6,500 rpm[1]
Ignition typeKick start: points (CDI ignition from 1978)
Transmission6-speed manual, chain final drive
Frame typeTubular twin cradle
SuspensionFront telescopic forks; rear swingarm with twin rear shock absorbers
BrakesSingle disc brake, front and rear
Rake, trail27.5°, 110 mm (4.3 in)
Wheelbase1,330 mm (52.5 in)
DimensionsW: 800 mm (31.5 in)
Seat height800 mm (31.5 in)
Weight165 kg (364 lb) (with 4.5 l; 1.2 US gal (1 imp gal) of fuel)[1] (wet)
Fuel capacity16.5 l (3.6 imp gal; 4.4 US gal)
Oil capacity1.6 litres (1.7 US qt)
Fuel consumption30 to 42 mpg‑imp (9.4 to 6.7 L/100 km; 25 to 35 mpg‑US)[1]

The brakes were single disc front and rear. It could complete a standing quarter-mile in 14.01 seconds.[1]

The RD400C was the first motorcycle by a major manufacturer to be fitted with cast wheels.[2]

In 1979 the RD was fitted with a capacitor discharge electronic ignition (CDI) unit as well as having thinner spoked cast wheels, a new foot peg position and some minor engine modifications.

See alsoEdit


  1. ^ a b c d e f "Bike". Bauer. May 1979. p. 71.
  2. ^ Dain Gingerelli (January 1993). "RD Days". Cycle World: 86. Retrieved 2015-06-17.[page needed]

External linksEdit