🏷️ Basic Information

Make:

Aprilia

Model:

RS125

Year:

2002

Type:

Sportbike

Engine Code:

Rotax 122

👋 Introduction

Positioning:

The Aprilia RS125 was a highly regarded lightweight sportbike, popular for its race-derived styling, agile handling, and sporty performance in the 125cc two-stroke class. It appealed to both younger riders seeking an accessible entry into sportbiking and experienced riders looking for a fun, track-day capable machine.

Competitors:

Competed directly with other premium 125cc two-stroke sportbikes such as the Yamaha YZF-R125 (though later model), Cagiva Mito, Honda NSR125, and Suzuki RG125.

Design Philosophy:

Emphasized performance, handling, and aggressive styling, mirroring Aprilia's racing heritage.

Engine Type:

Liquid-cooled, two-stroke, single-cylinder engine known for its spirited performance.

Chassis Features:

Deltabox-style aluminum frame, capable suspension components, and potent braking system for its class.

Diy Support:

Empowers DIY enthusiasts and mechanics with the necessary technical data and procedures to maintain and repair their 2002 Aprilia RS125 effectively.

📋 Manual Details

Primary Coverage:

Comprehensive repair and maintenance for the 2002 Aprilia RS125

Secondary Coverage:

DIY adjustments and troubleshooting

Page Count:

Approximately 300-400 pages (estimated based on typical factory service manuals for this class of motorcycle)

Manual Type:

Factory Service Repair Manual

Language:

English

Format:

Digital (PDF)

📖 Manual Coverage

Engine System:

Complete disassembly, assembly, inspection, and repair of the Rotax 122 engine (including top-end, bottom-end, lubrication, cooling, and fuel/air mixture systems).

Transmission System:

Gearbox inspection, repair, clutch assembly, and lubrication.

Chassis System:

Frame, swingarm, suspension (front forks and rear shock), steering system, and wheel bearing maintenance.

Braking System:

Hydraulic brake system components (calipers, master cylinders, lines), pad replacement, fluid flushing, and bleeding procedures.

Electrical System:

Wiring diagrams, ignition system (CDI, spark plug), lighting, starting system, charging system (alternator, battery), instrumentation, and sensor troubleshooting.

Fuel System:

Carburetor (Dell'Orto PHBH 28/AS or similar) tuning, cleaning, and jetting, fuel tank, fuel lines, and oil injection system.

Cooling System:

Radiator, coolant hoses, water pump, and thermostat maintenance.

Exhaust System:

Pipe and silencer inspection and maintenance.

Bodywork And Fairings:

Fairing removal, installation, and minor repair guidance.

Preventative Maintenance:

Scheduled maintenance tasks, lubrication points, and component checks.

Troubleshooting:

Diagnostic procedures for common starting, running, and electrical issues.

Disassembly And Assembly:

Step-by-step instructions for dismantling and reassembling all major motorcycle components.

Repair And Rebuild:

Detailed instructions for repairing or rebuilding engine, transmission, suspension, and brake systems.

Adjustments:

Carburetor adjustments, chain tension, clutch and brake lever adjustments.

Wiring Diagrams:

Color-coded electrical schematics for easy tracing of circuits.

Depth Level:

Comprehensive, covering from basic maintenance to complete engine and gearbox rebuilds, including detailed diagnostic procedures.

📊 Manual Specifications

File Format:

PDF

Searchability:

Text-searchable for quick information retrieval.

Printability:

Printable pages for workshop use.

Image Resolution:

High-resolution for clear diagrams and images.

Binding Type:

N/A (Digital format)

Paper Type:

N/A (Digital format)

⚙️ Engine Specifications

Engine Manufacturer:

Rotax

Engine Type:

Two-stroke single-cylinder

Displacement:

124.8 cc

Bore X Stroke:

54 mm x 54.5 mm

Cooling System:

Liquid-cooled

Intake System:

Reed valve induction

Horsepower Peak:

Approximately 30-34 HP (at crankshaft, depending on market regulations and tuning)

Torque Peak:

Approximately 20-22 Nm (at crankshaft)

Redline:

Around 10,500 - 11,500 RPM

Carburetor Model:

Dell'Orto PHBH 28/AS or similar

Fuel Delivery:

Pre-mix or Automatic Oil Injection system (depending on market/variant)

Fuel Type:

Unleaded gasoline (minimum 95 RON)

Oil Type Injection:

Fully synthetic 2-stroke oil (e.g., Motul 710 2T, Castrol Power 1 TTS)

🔧 Transmission

Transmission Type:

6-speed sequential manual gearbox

Clutch Type:

Wet multi-plate clutch

Final Drive:

Chain drive (520 pitch chain, typical gearing 16T front/48T rear)

Transmission Oil Type:

API GL-4 or GL-5 SAE 75W-90 synthetic gear oil (check manual for specific recommendation)

Transmission Oil Capacity:

Approximately 0.6 - 0.7 liters

📐 Dimensions

Length:

Approx. 1,970 mm

Width:

Approx. 720 mm

Height:

Approx. 1,145 mm

Wheelbase:

Approx. 1,345 mm

Dry Weight:

Approx. 141 kg

Wet Weight:

Approx. 158 kg (fully fueled and ready to ride)

Fuel Tank Capacity:

10.5 liters (including 2.5-liter reserve)

🛡️ Safety Features

Crash Test Ratings:

N/A (Motorcycle safety ratings are not standardized like passenger cars)

Braking System:

Dual disc front brakes (2 x 320mm discs, 4-piston calipers) and single disc rear brake (240mm disc, 2-piston caliper).

Suspension Type:

Upside-down telescopic forks (front), monoshock swingarm (rear)

Lighting:

Halogen headlamp, LED taillight

Frame Construction:

Lightweight aluminum alloy frame

💡 Technology Features

Infotainment System:

N/A (Focus is on core motorcycle mechanics and performance, not rider electronics).

Assistance Features:

N/A (No electronic rider aids like ABS or traction control on this model).

Ignition System:

CDI (Capacitor Discharge Ignition)

Reed Valve Technology:

Features sophisticated reed valve design for improved intake efficiency and power delivery.

🔧 Maintenance

Oil Change Engine:

Refer to manual for specific intervals, typically every 5,000-10,000 km or annually, but check gearbox oil condition.

Spark Plug Replacement:

Every 5,000-10,000 km, depending on plug type and usage.

Air Filter Cleaning:

Every 5,000 km or as needed based on riding conditions. Replace as per manual.

Chain Cleaning Lubrication:

Every 500-1,000 km or after riding in wet conditions.

Brake Fluid Flush:

Every 2 years or as recommended by the manual.

Coolant Replacement:

Every 2-3 years.

Engine Oil:

N/A (2-stroke, pre-mix or oil injection)

Transmission Oil:

SAE 75W-90 synthetic gear oil (API GL-4 or GL-5)

Coolant:

Ethylene glycol-based coolant, mixed 50/50 with distilled water.

Brake Fluid:

DOT 4 hydraulic brake fluid.

Carburetor Tuning:

Can be sensitive to altitude, temperature, and exhaust/airbox modifications. Proper jetting is crucial for optimal performance and preventing engine damage.

Power Valve Operation:

The mechanical power valve (AEX) can accumulate carbon and require periodic cleaning and lubrication to ensure proper function and avoid power band issues.

Engine Wear:

As a high-revving two-stroke, consistent and correct oil usage, and avoiding prolonged high-RPM operation without proper cooling, are key to longevity. Piston and ring wear are common with high mileage.

Electrical Connections:

Corrosion or loose connections in the wiring harness can lead to intermittent electrical issues. Regular inspection is recommended.

Suspension Seals:

Fork seals can sometimes leak, requiring replacement.

📚 Vehicle History

Manufacturer Origin:

Aprilia is an Italian motorcycle manufacturer with a strong pedigree in racing, particularly in smaller displacement classes.

Rs125 Development:

The RS125 line has a long history, evolving from earlier Aprilia 125cc two-stroke models. The 2002 model represents a mature iteration of the design, incorporating lessons learned from racing and road use.

Engine Legacy:

The Rotax 122 engine is a legendary two-stroke powerplant renowned for its power output and tuning potential, making the RS125 a popular choice for enthusiasts and track days.

Production Years:

The Aprilia RS125 was produced for many years, with the second generation (often referred to by its frame changes and styling updates) running through the early 2000s, including the 2002 model year.

🏆 Awards & Recognition

Industry Recognition:

The Aprilia RS125 (in its various iterations) has consistently been praised by motorcycle publications for its handling, braking, and the lively character of its two-stroke engine, often winning comparisons in the 125cc sportbike segment.