XJ 750 Seca

1981 Yamaha XJ 750 Seca Technical Analysis & Specification Breakdown

Engineered by Yamaha for the sport touring motorcycle segment, the 1981 Yamaha XJ 750 Seca pairs a 748 cc (45.6 cu in) air-cooled in-line four, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 82 HP (59.9 kW) at 9,000 rpm while maximum torque reaches 67 Nm (49.4 lb-ft) at 6,900 rpm, transferring power to the rear wheel through a 5-speed gearbox and shaft drive (cardan) final drive. With a specific output of 109.6 HP per liter and a 2,100 rpm working window between peak torque (6,900 rpm) and peak power (9,000 rpm), 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 XJ 750 Seca measures 241 kg (531 lbs) wet (curb), translating to a power-to-weight ratio of 0.34 HP/kg (2.94 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,445 mm (56.9 in) wheelbase engineered for balanced agility and highway composure. The 18-liter (4.8 US gal) fuel tank supports practical everyday commuting and weekend road stints, while factory top speed is listed at 204 km/h (127 mph).

Within MotoLibrary's Yamaha archive, this model family spans 2 indexed model years from 1981 to 1982, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.