Aprilia RS 125 Service Manual (2006)

Aprilia developed the RS 125 as the road-going expression of its lightweight racing culture. Aprilia's own later historical material traces the RS 125 name to 1992, while Piaggio Group's 2006 half-year report identifies a major new version launched in February 2006. That report describes the new sporting RS 125 as immediately taking a leading position in the 125 cc supersport segment, showing that the 2006 machine was treated as an important product renewal rather than simply another annual update. See the Piaggio Group 2006 half-year report.

The 2006 model retained the two-stroke architecture that had defined the RS 125 for years. Its liquid-cooled 124.82 cm³ single-cylinder engine uses reed-valve induction, separate automatic oil mixing and a Dell'Orto PHBH 28 carburettor. Factory data gives a 54 × 54.5 mm bore and stroke, 12.5:1 compression and an 11,000 rpm maximum engine speed. Power reaches the rear wheel through a cable-operated wet multi-plate clutch, six-speed gearbox and 17/40 chain final drive. Full-power configurations use Aprilia's electronically controlled RAVE exhaust valve to vary exhaust-port timing with engine speed, making this generation a characteristic two-stroke lightweight supersport.

The chassis remained equally central to the model's identity. A twin-spar frame with cast and stamped sections carries 17-inch alloy wheels, a hydraulically operated telescopic fork and an adjustable rear monoshock. Braking is handled by a 320 mm front disc and 220 mm rear disc. The factory specification lists a 1,345 mm wheelbase, 805 mm seat height and 137 kg running-order weight, giving the bike compact dimensions but full-size supersport proportions. The 2006 generation also brought revised road equipment including a multifunction digital instrument display, updated lighting hardware and a secondary-air system on relevant versions.

The RS 125's long commercial life was closely tied to Aprilia's racing image. Piaggio later stated that more than 100,000 two-stroke RS 125s had been produced and sold in more than 30 countries since 1993. The major successor break came in 2011 with the RS4 125, which Aprilia described as its first 125-class sport motorcycle with a four-stroke engine. The official RS4 125 launch release explicitly presents that model as the heir to the two-stroke RS 125, while noting that the two-stroke model remained available alongside the new RS4 at launch.

This listing is based specifically on factory workshop publication 8104976, Release 00/2006-03, first edition March 2006. Its reference section lists separate engine technical manuals, while this publication covers the motorcycle's servicing, chassis, fuel system, engine removal and installation, RAVE system, cooling and electrical systems. The source does not establish blanket 2005-2013 applicability, so catalog coverage remains verified for 2006 only. For the preceding generation, see the earlier Aprilia RS 125 workshop documentation.