Segment:
Lightweight Sport Motorcycle (125cc class equivalent for licensing in many regions)
Target Audience:
Enthusiast riders, aspiring racers, DIY mechanics seeking in-depth knowledge
Key Competitors:
Aprilia RS125, Yamaha TZR50/RD50, Suzuki RGV50, Honda NSR50, Cagiva Mito 50
Sporty Design:
Aggressive styling, clip-on handlebars, rear-set footpegs, race-inspired fairings
Performance Orientation:
High-revving two-stroke engine, capable chassis, powerful brakes for its class
Handling:
Nimble and agile handling, good feedback from the chassis and suspension
Primary Coverage:
Comprehensive Service, Repair, and Workshop Procedures
Secondary Coverage:
Maintenance, Troubleshooting, Diagnostics, Wiring Diagrams, Specifications
Estimated Page Count:
Approximately 200-300 pages (typical for this model and era's comprehensive manuals)
Type:
Service Repair Workshop Manual
Engine Mechanical:
Disassembly, assembly, inspection, tuning, lubrication, cooling system
Engine Management:
Carburetor tuning and rebuilding (Dell'Orto PHVA 17.5/18), ignition system, sensors
Fuel System:
Fuel tank, fuel lines, fuel pump (if applicable), carburetor
Transmission:
Gearbox operation, clutch system (wet multi-plate), lubrication, adjustment
Chassis And Frame:
Frame inspection, steering system, fork (upside-down), shock absorber, swingarm
Brakes:
Front and rear disc brake systems, hydraulic lines, caliper service, bleeding procedures
Electrical System:
Wiring diagrams, battery, starter motor, lighting, indicators, horn, dashboard instruments
Cooling System:
Radiator, hoses, coolant, thermostat operation
Wheels And Tires:
Wheel bearing service, tire pressure, tire replacement
Bodywork And Trim:
Fairings, seat, fuel tank cover, fenders, removal and installation
Preventative Maintenance:
Regular checks, lubrication points, fluid level monitoring, chain adjustment
Troubleshooting:
Diagnostic guides for common problems, symptom-based troubleshooting charts
Engine Rebuild:
Top-end rebuild (cylinder, piston, rings), bottom-end service, crankshaft inspection
Carburetor Adjustment:
Idle speed, air-fuel mixture, jetting changes for altitude/modification
Clutch Service:
Clutch plate replacement, spring inspection, clutch lever adjustment
Brake System Maintenance:
Brake pad replacement, fluid flushing and replacement, caliper piston service
Suspension Servicing:
Fork oil change, rear shock absorber inspection and adjustment
Electrical Diagnostics:
Component testing, short circuit detection, wiring harness repair
Wheel Alignment:
Steering head bearing adjustment
Depth:
Comprehensive, covering routine maintenance to complete engine and chassis rebuilds
Diagnostic Capability:
Advanced, with specific troubleshooting flowcharts and component testing procedures
Rebuild Detail:
Detailed step-by-step instructions for all major mechanical components
Engine Type:
Two-stroke, single-cylinder, liquid-cooled
Bore X Stroke:
39.5 mm x 40.5 mm
Compression Ratio:
Approximately 8.5:1 (varies slightly with tuner)
Lubrication System:
Pre-mix or Automatic Oil Injection (depending on market variant)
Horsepower Approx:
10-15 hp (factory restricted for class regulations, tunable)
Torque Approx:
7-10 Nm (factory restricted)
Carburetor Model:
Dell'Orto PHVA 17.5 RD / PHVA 18
Fuel Type:
Unleaded Gasoline (95 RON recommended), 2-stroke oil mix
Fuel Tank Capacity:
13 Liters
Crash Test Results:
N/A (Motorcycle, not subject to standard automotive crash testing)
Braking System:
Hydraulic disc brakes front and rear for effective stopping power
Suspension Stability:
Upside-down front forks and adjustable rear monoshock contribute to stable handling
Lighting:
Headlight, taillight, brake lights, turn signals for visibility
Frame Integrity:
Deltabox-style aluminum frame for structural rigidity
Oil Change Engine:
Refer to manual; often based on mileage or hours for 2-stroke, but focus is on fuel/oil mix quality.
Spark Plug Replacement:
Approximately every 3,000 - 6,000 km, depending on plug type and usage.
Air Filter Cleaning:
Every 2,000 - 4,000 km, or more frequently in dusty conditions.
Chain Lubrication Adjustment:
Every 500 km or after riding in wet conditions.
Brake Fluid Flush:
Every 12-24 months, or as recommended by fluid manufacturer.
Engine Oil:
High-quality 2-stroke premix oil (e.g., Motul 7100 2T, Castrol TTS). Refer to manual for specific ratio.
Transmission Oil:
API GL-3 or GL-4 SAE 75W/90 or 80W/90 Gear Oil. Capacity: Approx. 0.8 - 1.0 Liters.
Coolant:
Ethylene glycol based coolant with anti-corrosion additives. Mix ratio 50/50 with distilled water. Capacity: Approx. 0.7 - 0.8 Liters.
Brake Fluid:
DOT 4 recommended.
Carburetor Blockages:
Can occur if fuel is left sitting for long periods; requires cleaning and fresh fuel.
Power Valve Sticking:
Carbon buildup can cause the exhaust power valve to stick, affecting performance; requires regular cleaning.
Clutch Wear:
Aggressive riding can lead to premature clutch wear, requiring clutch plate replacement.
Electrical Connections:
Corrosion or loose connections can cause intermittent electrical issues; inspection and cleaning are important.
Manufacturer:
Aprilia is an Italian manufacturer with a strong pedigree in racing, particularly in smaller displacement categories.
Predecessor:
The RS50 is part of a lineage of Aprilia's small-displacement sportbikes, evolving from earlier models like the AF1 Futura 50.
Development:
The 2003 model represents an update to the RS50 platform, often incorporating revised styling and minor mechanical tweaks from previous years.
Manufacturing Location:
Italy
Production Years:
The RS50 was produced through various iterations from the early 1990s up to around 2010, with significant updates occurring periodically.
