This comprehensive service and repair manual is specifically designed for Aprilia RS125 motorcycles manufactured between 1999 and 2003. It provides detailed instructions and guidance for all aspects of maintenance, repair, and restoration, making it an indispensable resource for both novice and experienced mechanics. The manual covers a wide range of topics, including:

* **General Information:** Get acquainted with your Aprilia RS125, understanding its specifications, features, and operating principles.
* **Maintenance:** Learn essential maintenance procedures, including regular checks, fluid changes, and adjustments, to keep your motorcycle running smoothly.
* **Gearbox & Clutch:** Dive into the inner workings of the gearbox and clutch system, gaining a thorough understanding of their operation and troubleshooting techniques.
* **Engine Removal and Installation:** The manual walks you through the process of removing and reinstalling the engine, providing detailed instructions and important considerations.
* **Engine Fuel System:** Learn about the intricacies of the fuel system, including fuel injection, carburetors, and fuel lines, with detailed descriptions and troubleshooting tips.
* **Engine Lubrication and Cooling:** Understand the importance of proper lubrication and cooling systems, covering oil changes, radiator maintenance, and related components.
* **Engine Combustion System:** Explore the workings of the combustion system, including spark plugs, ignition timing, and air intake, with comprehensive explanations and repair procedures.
* **Lubrication System:** Get in-depth knowledge about the lubrication system, including oil pumps, filters, and lines, with detailed instructions for maintenance and repair.
* **Cylinder Head/Valves:** Understand the intricacies of the cylinder head and valves, learning about valve adjustments, head gasket replacement, and related procedures.
* **Alternator/Starter Clutch:** Explore the operation and maintenance of the alternator and starter clutch, with detailed descriptions and troubleshooting guidance.
* **Crankcase/Piston/Cylinder:** Delve into the crankcase, piston, and cylinder components, learning about their functions and repair procedures.
* **Crankshaft/Transmission/Balancer:** Gain comprehensive knowledge about the crankshaft, transmission, and balancer systems, with detailed instructions for maintenance and repair.
* **Transmission System:** Understand the workings of the transmission system, including gears, shafts, and related components, with detailed repair procedures.
* **Front Wheel and Steering System:** Explore the front wheel and steering system, learning about wheel bearings, forks, and steering adjustments.
* **Rear Wheel System:** Gain insight into the rear wheel and suspension components, including wheel bearings, swingarm, and shock absorbers.
* **Fenders and Exhaust Pipe:** Learn about the maintenance and repair of fenders and exhaust systems, including replacement procedures and troubleshooting tips.
* **Periodic Checks & Adjustments:** Stay on top of routine checks and adjustments, ensuring your motorcycle remains in peak condition.
* **Chassis:** Understand the construction and maintenance of the chassis, including frame, swingarm, and related components.
* **Cooling System:** Learn about the cooling system, including the radiator, fan, and coolant, with detailed instructions for maintenance and repair.
* **Fuel Injection System:** Explore the intricacies of the fuel injection system, including injectors, sensors, and control unit, with detailed descriptions and troubleshooting tips.
* **Braking System:** Gain comprehensive knowledge about the braking system, including calipers, discs, pads, and master cylinders, with detailed repair procedures.
* **Suspension:** Understand the workings of the suspension system, including forks, shock absorbers, and related components, with detailed instructions for adjustment and repair.
* **Electrical System:** Delve into the electrical system, covering wiring diagrams, battery, charging system, lights, and switches, with comprehensive explanations and troubleshooting guidance.
* **Body & Fixtures:** Learn about the maintenance and repair of body panels, mirrors, and other fixtures, including replacement procedures and troubleshooting tips.
* **Frame/Body Panels/Exhaust System:** Gain insight into the repair and replacement of the frame, body panels, and exhaust system, with detailed instructions and guidance.
* **Wheels & Tyres:** Understand the proper care and maintenance of wheels and tires, including tire pressure, balancing, and replacement procedures.
* **Battery/Charging System:** Learn about the operation and maintenance of the battery and charging system, with detailed instructions for testing and replacement.
* **Ignition System:** Explore the workings of the ignition system, including ignition coil, spark plugs, and timing, with detailed descriptions and troubleshooting tips.
* **Electric Starter:** Learn about the operation and troubleshooting of the electric starter system, with detailed instructions for testing and repair.
* **Lights/Meters/Switches:** Understand the function and repair of lights, meters, and switches, with detailed descriptions and troubleshooting tips.
* **Wiring Diagrams:** Utilize the comprehensive wiring diagrams to troubleshoot electrical issues and understand the electrical system's layout.
* **Technical Information & Specifications:** Access essential technical information and specifications, including engine dimensions, torque values, and other vital data.
* **Troubleshooting:** Utilize the troubleshooting sections to diagnose and resolve common issues, providing step-by-step guidance for a wide range of problems.
* **Index:** Easily locate the information you need with a comprehensive index that provides quick access to specific topics.

This manual provides everything you need to keep your Aprilia RS125 running smoothly and efficiently, empowering you to perform routine maintenance, tackle challenging repairs, and restore your motorcycle to its former glory.

The Aprilia RS125, a legendary name in the world of small-displacement performance motorcycles, was a true icon of its time. Born in 1999, the RS125 represented the pinnacle of Italian engineering and design, captivating riders with its sleek, aggressive aesthetics and exhilarating performance. Its sharp lines, flowing curves, and unmistakably sporty silhouette screamed speed and agility. The RS125 was not merely a commuter but a symbol of passion, a machine that embodied the spirit of racing.

Underneath the stunning aesthetics, the RS125 housed a potent, liquid-cooled, single-cylinder engine that delivered a thrilling ride. The 125cc engine, featuring a reed valve intake and a meticulously engineered exhaust system, churned out impressive power for its class. The RS125's performance was further enhanced by its lightweight, tubular steel frame and its precise, responsive suspension, allowing for nimble handling and confident cornering. The bike was meticulously crafted, with high-quality components throughout, ensuring reliability and durability. Its lightweight, agile handling, and impressive power output made the Aprilia RS125 a true joy to ride, a machine that instilled confidence both on the road and on the track. These qualities cemented its place as a favorite among aspiring racers and passionate enthusiasts.