Hyosung GT650S / GT650R Comet Service Manual Supplement (2005)

Hyosung expanded its 647 cm³ GT platform beyond the original naked roadster by adding the GT650S and GT650R as more sporting derivatives. Both retained the same liquid-cooled 90-degree DOHC V-twin, six-speed transmission and chain final drive used by the naked GT650, but changed the riding position, bodywork and equipment to target riders who wanted more wind protection and a more performance-oriented appearance. The factory's April 2005 supplement documents these S/R differences directly, confirming that both variants were established parts of the Comet 650 family by that model year.

The GT650S occupied the middle ground between naked roadster and supersport styling. Hyosung offered it in standard and sport-type configurations depending on market, with a half-fairing, windscreen and more protected cockpit than the base GT650. Rider Magazine's later GT650S road test describes the same 647 cm³ carbureted V-twin shared by the GT650R and GV650 and emphasizes the S model's upright but sporty road-bike character. The factory supplement also records model-specific changes to bodywork, controls, lighting, combination meter, footrest adjustment and steering service.

The GT650R pushed the same platform further toward a sportbike identity with a full fairing and lower bodywork. Its chassis remained closely related to the S, using 17-inch radial tires, twin front discs, rear disc brake, 120 mm fork travel and the same 1,435 mm wheelbase. The two models therefore formed a faired 650 cc V-twin sport platform rather than separate mechanical families: most engine, transmission and core service procedures remained those of the base GT650, while the supplement concentrated on the S/R-specific equipment and chassis differences.

The carbureted S/R generation continued through the later 2000s before Hyosung made a major technical update to the whole 650 range. Bikesales reported in 2009 that the GT650, GT650S, GT650R and GV650 were all moving to electronic fuel injection for the 2010 model year, together with revised styling and braking hardware. Bikesales' EFI launch coverage marks a clear generational break from the twin-BDSR39 carburetor configuration documented by this 2005 supplement.

This listing is specifically for Hyosung Service Manual Supplement No. 99000-94910, marked “1st Ed. APR. 2005.” Its foreword states that it covers the differences for Comet 650S and Comet 650R and refers technicians to the base Comet 650 service manual No. 99000-94810 for procedures not repeated here. Because the supplement itself is dated and scoped to the 2005 S/R specification, catalog coverage is conservatively limited to 2005. Related publications are grouped in the Hyosung Comet manual catalog.