165 kg (364 lb) (with 4.5 l; 1.2 US gal (1 imp gal) of fuel) (wet)
16.5 l (3.6 imp gal; 4.4 US gal)
1.6 litres (1.7 US qt)
30 to 42 mpg‑imp (9.4 to 6.7 L/100 km; 25 to 35 mpg‑US)
The RD400 is a 399 cc (24.3 cu in) two-strokeair 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.)
The brakes were single disc front and rear. It could complete a standing quarter-mile in 14.01 seconds.
The RD400C was the first motorcycle by a major manufacturer to be fitted with cast wheels.
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.