XT 660 R

2004 Yamaha XT 660 R Technical Analysis & Specification Breakdown

Built around Yamaha's enduro - offroad motorcycle platform, the 2004 Yamaha XT 660 R pairs a 659 cc (40.2 cu in) liquid-cooled single cylinder, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 48 HP (35 kW) at 6,000 rpm while maximum torque reaches 58.4 Nm (43.1 lb-ft) at 5,250 rpm, transferring power to the rear wheel through chain final drive. With a specific output of 72.8 HP per liter and a 750 rpm working window between peak torque (5,250 rpm) and peak power (6,000 rpm), the engine character is indicating a tractable, stress-free state of tune focused on everyday usability and broad torque delivery.

On the scales, the XT 660 R measures 165 kg (364 lbs) dry, translating to a power-to-weight ratio of 0.29 HP/kg (3.44 kg per horsepower). Rider ergonomics and chassis geometry center around a 855 mm (33.7 in) seat height — reflecting a long-travel chassis stance that favors ground clearance and off-pavement control, combined with a 1,500 mm (59.1 in) wheelbase engineered for balanced agility and highway composure.

Within MotoLibrary's Yamaha archive, this model family spans 2 indexed model years from 2004 to 2007, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.