Basic Information Identification Make: Yamaha Model: YJ125S Year: 2003 Codes Chassis Code: YJ125S Introduction Market Position Vehicle Segment: Lightweight scooter, commuter-focused Competitive Analysis Competitors: Honda PCX, SYM Fiddle, Kymco Agility (segment competitors) Key Features Vehicle Purpose: Designed for urban commuting, offering fuel efficiency and ease of operation Manual Value Proposition: Empowers owners and technicians with comprehensive knowledge for reliable maintenance and repair, reducing reliance on expensive dealership services. Manual Details Coverage Areas Areas Covered: Full Service, Repair, Maintenance, Rebuild, Refurbish, Restoration Page Count Estimated Page Count: 300-500 Manual Type Type: Full Service & Repair Manual Language Language: English Format Format: PDF Download Manual Coverage Systems Covered Engine: Complete engine disassembly, assembly, troubleshooting, tuning, and diagnostics Transmission: Automatic transmission (CVT) inspection, adjustment, and repair Fuel System: Carburetor overhaul, fuel pump, fuel lines, and fuel tank maintenance Electrical System: Wiring diagrams, ignition system, lighting, battery, charging system, starter, and accessories Brakes: Front and rear brake system inspection, service, and hydraulic component replacement Suspension: Front fork service, rear shock absorber replacement, and linkage maintenance Cooling System: Radiator, coolant, and fan system maintenance and repair Exhaust System: Muffler, catalytic converter, and exhaust pipe inspection and replacement Frame And Body: Chassis inspection, fairing removal/installation, seat maintenance Wheels And Tires: Tire inspection, replacement, wheel bearing service, and balancing Procedures Included Maintenance: Scheduled maintenance, oil changes, filter replacements, spark plug service, valve adjustments Troubleshooting: Diagnostic procedures for common and uncommon problems, fault finding guides Repair: Step-by-step instructions for component removal, installation, and repair Rebuild: Comprehensive procedures for engine and transmission rebuilds Specifications: Torque specifications, clearances, fluid capacities, and electrical values Technical Depth Depth: In-depth coverage from basic user maintenance to complete mechanical and electrical overhauls Manual Specifications File Format Quality: High-resolution, searchable PDF with clear text and diagrams Print Quality Printability: Printable pages for easy workshop reference Binding Type Binding: N/A (PDF Download) Paper Type Paper: N/A (PDF Download) Engine Specifications Primary Engine Engine Type: Four-stroke, SOHC, single-cylinder Displacement: 125cc Bore X Stroke: 52.4 mm x 57.9 mm Compression Ratio: 10.2:1 (Typical) Cooling System: Forced air cooling Performance Horsepower: Approx. 9.5 - 10.5 HP (at RPM TBD in manual) Torque: Approx. 9 - 10 Nm (at RPM TBD in manual) Fuel System Fuel Delivery: Carburetor (specific model/size TBD in manual) Fuel Type: Unleaded gasoline Fuel Tank Capacity: Approx. 5.0 - 6.0 Liters (TBD in manual) Carburetor Specifications: Detailed settings, jet sizes, and adjustment procedures covered Transmission Standard Type: Automatic Continuously Variable Transmission (CVT) Optional Options: N/A (CVT is standard) Features Drive Type: Belt drive to rear wheel Clutch Type: Automatic centrifugal clutch Transmission Fluid: Specific type and capacity covered in manual Dimensions Exterior Overall Length: Approx. 1900 - 1950 mm (TBD) Overall Width: Approx. 700 - 750 mm (TBD) Overall Height: Approx. 1100 - 1150 mm (TBD) Weights Dry Weight: Approx. 115 - 125 kg (TBD) Curb Weight: Approx. 120 - 130 kg (TBD) Max Load Capacity: Typically 150-170 kg including rider (TBD) Safety Features Ratings Safety Standards: Compliance with relevant national and international motorcycle safety standards Active Features Brakes: Front disc brake, Rear drum brake (standard configuration) Lighting: Halogen headlight, LED taillight/brake light, turn signals Passive Features Frame Construction: Steel tube frame designed for stability and rider comfort Parking Brake: Often incorporates a parking brake mechanism (details in manual) Technology Features Infotainment Dashboard: Analog speedometer, fuel gauge, indicator lights (turn signals, oil, high beam). Detailed explanation in manual. Driver Assistance Assist Features: N/A (basic scooter technology) Connectivity Connectivity Features: N/A Maintenance Service Intervals Oil Change: Every 3,000 - 5,000 km or 6 months (refer to manual for precise interval and oil type) Air Filter: Inspect every 5,000 km, clean/replace as needed (details in manual) Spark Plug: Replace every 10,000 - 15,000 km (specific plug type and gap in manual) Valve Clearance: Check/adjust every 10,000 - 20,000 km (critical procedure detailed in manual) Fluid Specifications Engine Oil Type: Yamaha recommends specific API SG or higher, JASO MA certified oil, e.g., Yamalube 4-stroke motor oil 10W-40 (verify in manual) Engine Oil Capacity: Approx. 0.8 - 1.0 Liters (without filter change), 1.0 - 1.2 Liters (with filter change) - precise amount in manual Brake Fluid Type: DOT 3 or DOT 4 (verify in manual) Coolant Type: Ethylene glycol-based antifreeze (specific mixture ratio in manual) Known Issues Common Problems: Potential for carburetor clogging if fuel sits, CVT belt wear over time, occasional electrical connection issues. Manual provides diagnosis. Preventative Maintenance: Regular cleaning of air filter, proper fuel management, and timely oil changes are crucial for longevity. Manual details all preventative measures. Vehicle History Brand Heritage Yamaha Legacy: Yamaha's long-standing reputation for building reliable and performance-oriented motorcycles and scooters. Model Evolution Yj125S Positioning: Part of Yamaha's range of accessible and practical scooters, evolving from earlier models. Production Manufacturing Origin: Likely manufactured in Southeast Asia (e.g., Indonesia or Vietnam), a common production...