DT 400

1977 Yamaha DT 400 Technical Analysis & Specification Breakdown

Positioned in Yamaha's enduro - offroad motorcycle lineup, the 1977 Yamaha DT 400 utilizes a 397 cc (24.2 cu in) air-cooled single cylinder, two-stroke layout. In factory specification, peak output is rated at 21 HP (15.3 kW) at 5,600 rpm while maximum torque reaches 37.3 Nm (27.5 lb-ft) at 5,000 rpm, transferring power to the rear wheel through a 5-speed gearbox and chain final drive. With a specific output of 52.9 HP per liter and a 600 rpm working window between peak torque (5,000 rpm) and peak power (5,600 rpm), the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.

On the scales, the DT 400 measures 141 kg (311 lbs) wet (curb), translating to a power-to-weight ratio of 0.15 HP/kg (6.71 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,410 mm (55.5 in) wheelbase engineered for quick, flickable steering geometry. The 9-liter (2.4 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 136 km/h (85 mph).

Within MotoLibrary's Yamaha archive, this model family spans 3 indexed model years from 1975 to 1977, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.