The GR650 was a standard motorcycle built by Suzuki. In the United States it was the GR650 Tempter, and worldwide as simply GR650. The GR650, saddled with the "Tempter" name, was only available in the United States for 2 years, as 1983 and 1984 models. The GR650 was produced from 1983 to 1989, The GR650 featured an air-cooled DOHC parallel twin engine with chain drive and was designed for nimble handling. It featured a two-stage flywheel which used a centrifugal clutch to lower flywheel mass above 3,000 RPM.[1] This was intended to provide easier take-off at low RPM and better reponsiveness at higher RPMs. It also featured a progressive mono-shock rear suspension.
To induce better swirling of the air-fuel mixture in the GR650 engine, Suzuki used a "sub-intake port," which ran a tube from the carburetor throat to the intake port just above the valve head. Suzuki claimed that this allows the GR650 to run with a leaner mixture than usual, which improves economy.[2]
From July 1983 Cycle World