🏷️ Basic Information

Make:

Aprilia

Model:

RS125

Sub Model:

Sport Production

Engine Code Variant:

Rotax 122

Applicable Years:

1993-2003

👋 Introduction

Positioning:

The Aprilia RS125 was a highly regarded lightweight sportbike, known for its performance, handling, and racing pedigree, appealing to younger riders and track day enthusiasts. This manual targets owners and independent mechanics seeking to maintain or repair this specific model.

Competitors:

Competed with other 125cc two-stroke sportbikes of its era, such as the Yamaha TZR125, Honda NSR125, and Cagiva Mito 125.

Features:

This manual provides the essential technical information required to keep the Aprilia RS125 operating at its peak performance and to address common wear and tear issues prevalent in a high-performance two-stroke machine.

📋 Manual Details

Systems Covered:

Engine, Fuel System, Cooling System, Lubrication, Chassis, Electrical System, Troubleshooting

Estimated Page Count:

300-400 pages (estimated based on comprehensive coverage)

Type:

Service and Repair Manual

Language:

English

Format:

Digital (likely PDF)

📖 Manual Coverage

Engine:

Detailed breakdown of the Rotax 122 two-stroke engine, including top-end (cylinder, piston, rings), bottom-end (crankshaft, connecting rod, bearings), and valve systems (if applicable to specific iterations).

Fuel System:

Carburetor tuning and rebuilding (likely Dell'Orto PHBH/VHSH), fuel lines, fuel pump (if equipped), fuel tank maintenance, and fuel petcock operation.

Cooling System:

Radiator, coolant hoses, water pump, thermostat operation, and coolant flushing/refilling procedures.

Lubrication:

Oil injection system diagnostics and maintenance, gearbox oil change procedures, and chassis lubrication points.

Chassis:

Frame inspection, suspension adjustments (front forks, rear shock), steering head bearing maintenance, wheel bearing service, brake system overhaul (pads, discs, lines, calipers), and general chassis component inspection.

Electrical System:

Wiring diagrams for various model years, battery maintenance, lighting system troubleshooting, ignition system components (spark plug, CDI, coil), starter motor operation, and switchgear diagnostics.

Troubleshooting:

Diagnostic charts for common performance issues, starting problems, electrical faults, and mechanical failures, with suggested solutions.

Maintenance:

Regular service intervals, oil changes, filter replacements, spark plug checks, chain adjustment, brake fluid replacement, and coolant flushes.

Repair:

Engine rebuilds (piston replacement, seal replacement), carburetor rebuilds, brake caliper overhauls, suspension fork seal replacement, and electrical component replacement.

Diagnostics:

Identifying causes of engine misfires, poor performance, charging system issues, and braking problems using provided troubleshooting guides.

Installation:

Guidelines for replacing common wear items and components.

Depth:

Comprehensive. Covers from basic routine maintenance to in-depth engine disassembly and reassembly, electrical diagnostics, and chassis component overhauls.

📊 Manual Specifications

Format Details:

Likely a searchable PDF document, optimized for digital viewing and printing of specific sections.

Quality:

High-resolution scans or professionally produced digital content, ensuring clarity of diagrams and text.

Binding:

N/A (Digital Format)

Paper:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Type:

Two-stroke, liquid-cooled, single-cylinder (Rotax 122)

Bore X Stroke:

54 mm x 54.5 mm (typical)

Displacement:

124.8 cc

Compression Ratio:

Approx. 12.5:1 to 13.5:1 (depending on version)

Power Output:

Approx. 28-34 hp @ 10,500 rpm (depending on market and tuning)

Torque:

Approx. 18-20 Nm @ 9,500 rpm (depending on market and tuning)

Ignition System:

Electronic CDI (Capacitor Discharge Ignition)

Ignition Timing:

Specific advance figures provided in manual (e.g., 1.5-2.0 mm Before TDC).

Spark Plug:

NGK BR9EG or equivalent (typical)

Top Speed:

Approx. 150-160 km/h (depending on rider and conditions)

Carburetor:

Dell'Orto PHBH 28/30 or VHSH 30 (common variants), with specific jetting and needle settings detailed.

Fuel Type:

Unleaded gasoline, minimum 95 RON (Octane rating is critical for two-strokes).

Oil Injection:

Automatic oil injection system with separate oil reservoir.

Two Stroke Oil Spec:

High-quality synthetic two-stroke oil meeting JASO FD or ISO-L-EGD standards.

🔧 Transmission

Type:

6-speed sequential manual gearbox

Clutch:

Wet multi-plate clutch

Gear Ratios:

Specific ratios for each gear are detailed within the manual.

Features:

Close-ratio gearbox designed for sporty performance.

Gearbox Oil Type:

SAE 75W/90 or SAE 80W API GL-4 or GL-5 (check manual for exact specification).

Gearbox Oil Capacity:

Approx. 0.8 - 1.0 liters (check manual for exact capacity).

📐 Dimensions

Length:

Approx. 1980 mm (varies slightly by year)

Width:

Approx. 700 mm (varies slightly by year)

Height:

Approx. 1100 mm (varies slightly by year)

Wheelbase:

Approx. 1370-1380 mm

Dry Weight:

Approx. 130-135 kg

Fuel Tank Capacity:

Approx. 11-12 liters

Front Tire Size:

110/70-17 M/C 54S (typical)

Rear Tire Size:

150/60-17 M/C 66S (typical)

Wheel Type:

Alloy wheels

Wheel Bolt Pattern:

N/A (typical motorcycle hub mounting)

🛡️ Safety Features

Safety Ratings:

N/A (Motorcycles are not typically rated by consumer safety organizations like NHTSA or Euro NCAP in the same way as cars.)

Braking System:

Front: Dual hydraulic disc brakes with 4-piston calipers. Rear: Hydraulic disc brake with 2-piston caliper.

Suspension Type:

Front: Telescopic forks (often upside-down), adjustable preload/damping. Rear: Monoshock swingarm, adjustable preload and rebound damping.

Lighting:

Halogen headlight, LED tail light (depending on year), turn signals.

Frame Construction:

Aluminum alloy perimeter frame.

💡 Technology Features

Infotainment System:

N/A (This is a 1990s era sportbike; no integrated infotainment systems.)

Driver Assistance Features:

N/A (No electronic rider aids like ABS, traction control, etc. on these models.)

Connectivity Features:

N/A (No connectivity features.)

Engine Management:

Basic CDI ignition system. Carburetor controls fuel/air mixture. The manual details all settings and diagnostic steps for these systems.

🔧 Maintenance

Oil Change Gearbox:

Every 6,000-8,000 km or annually (check manual for precise interval).

Spark Plug Replacement:

Every 4,000-6,000 km or as needed based on inspection.

Air Filter Cleaning:

Every 3,000-5,000 km or more frequently in dusty conditions.

Coolant Flush:

Every 2 years or as specified by coolant manufacturer.

Coolant Type:

Ethylene glycol based antifreeze, mixed 50/50 with distilled water. Specific coolant recommendations might be in manual.

Coolant Capacity:

Approx. 1.2-1.4 liters (check manual for exact capacity).

Engine Wear:

Piston and ring wear due to high-revving nature; potential for cylinder scoring if proper cooling and lubrication are not maintained; reed valve wear. The manual details inspection procedures.

Electrical Gremlins:

Wiring harness issues, stator/alternator failures, and regulator/rectifier problems are not uncommon on older European motorcycles. The electrical diagrams in the manual are crucial for diagnosis.

Carburetor Tuning:

Sensitivity to altitude, temperature, and exhaust modifications, requiring careful jetting adjustments. The manual provides baseline settings.

Clutch Wear:

Clutch plate wear is accelerated with aggressive riding. Manual covers clutch inspection and replacement.

📚 Vehicle History

Heritage:

Aprilia, an Italian manufacturer, has a strong racing heritage, particularly in Grand Prix motorcycle racing. The RS125 is a direct beneficiary of this racing DNA, translating track performance to the street.

Evolution:

The RS125 was produced for many years, with various updates to styling, components, and engine tuning. The models covered (1993-2003) represent a significant period of its development, featuring the potent Rotax 122 engine and sophisticated chassis.

Production Period:

The RS125 platform was produced from the early 1990s through to the early 2010s, with significant revisions.

🏆 Awards & Recognition

Industry Awards:

While specific awards might be hard to pinpoint for individual model years, the Aprilia RS125 platform consistently received praise in motorcycle publications for its performance, handling, and race-replica styling throughout its production run.

Performance Ratings:

Highly rated by enthusiasts and magazines for its class-leading power and track-day capability.

Certifications:

N/A (Motorcycle specific certifications are not applicable here.)