The Yamaha XT 660 was a dual-purpose motorcycle that debuted as a replacement model for the Yamaha XT 600. The bike was powered by a 660cc liquid-cooled single-cylinder engine and was suitable for both paved and unpaved trails.
Alongside the XT 660 model, Yamaha produced two other versions, including a more street-oriented supermoto named XT 660X and an adventure-touring version designated as Yamaha XT 660Z Tenere.
In 2006, the Japanese motorcycle manufacturer launched the Yamaha XT 660X, a dual-purpose motorcycle that featured the same specifications as previous models without any significant modifications whatsoever.
The 2006 Yamaha XT 660X had installed a 659cc four-stroke liquid-cooled single-cylinder engine managed by a fuel injection system. As for the power figures, the power unit provided 48 hp with a peak force at 6,000 rpm and 58 Nm (43 lb-ft) torque at 5,250 rpm.
Holding the engine, a steel tubular diamond frame was fitted with a 43 mm telescopic fork on the front end, providing 225 mm of travel, and a monocross suspension system on the rear, delivering 200 mm of travel and handling the bike's suspension.
As for the braking power, the bike relied on a 320 mm disc grabbed by a four-piston caliper on the front wheel and a 245 mm disc managed by a single-piston caliper on the rear wheel, delivering optimum braking performance.