The GR650 features a 650 cm³ 4-stroke DOHC 2-cylinder engine equipped with Suzuki Twin Dome Combustion Chambers (STDCC). This model incorporates a new variable mass mechanism designed to prevent revolving force loss by automatically disengaging the crankshaft above approximately 3,000 rpm. This mechanism realizes smoother revs at low rpms while ensuring dynamic acceleration in the mid- and high-rpm ranges. The weight and size of the engine were reduced by adopting a hollow camshaft and single-shaft balancer. In addition to reducing weight (the dry weight of the GR650 is only 178 kg) the adoption of air induction and oil jet piston ring cooling systems achieves a superb balance between agile acceleration performance and excellent fuel economy.

Dimensions and weight	Dimensions	Overall length	2,120 mm
		Overall width	850 mm
		Overall height	1,180 mm
	Wheelbase		1,430 mm
	Weight		178 kg (Dry)
Engine	Engine type		4-stroke, 2-cylinder, air-cooled, DOHC
	Engine displacement		651 cm³
	Bore x stroke		77.0 mm × 70.0 mm
	Maximum power		39.0kW(53PS) / 7,000rpm
	Maximum torque		54.9N-m / 6,000rpm
Transmission			5-speed constant mesh
Front tire size			100/90-19 57H
Rear tire size			130/90-16 67H