The Yamaha YJ125 is a versatile and reliable lightweight scooter designed primarily for urban commuting. Produced from 2003 through 2010, this model offers a balance of fuel efficiency and maneuverability, making it an excellent choice for navigating city streets. Its robust four-stroke, air-cooled engine provides dependable performance, while the automatic CVT transmission ensures a smooth and effortless riding experience. Known for its practicality and commitment to quality engineering, the YJ125 stands as a solid option in its segment, built to provide consistent service for daily transportation needs. This comprehensive Workshop Service Repair Manual serves as an essential guide for maintaining and repairing the Yamaha YJ125. It covers a wide array of critical systems, including detailed procedures for engine disassembly and assembly, transmission and drivetrain maintenance, chassis and suspension adjustments, and brake system servicing. Furthermore, the manual provides in-depth information on the electrical system, fuel system components, and bodywork. With step-by-step instructions, troubleshooting guides, and clear wiring diagrams, this resource is invaluable for owners and technicians alike, ensuring the YJ125 remains in optimal working condition throughout its service life. 🏷️ Basic Information Identification Make: Yamaha Model: YJ125 Codes Internal Model Code: YJ125 (Model variations may exist depending on region) 👋 Introduction Market Position Vehicle Segment: Lightweight scooter, utility/commuter segment Competitive Analysis Competitors: Honda Lead 125, Suzuki Address 125, Kymco Agility 125, SYM Jet 125 (depending on specific market) Key Features Design Purpose: Designed for urban commuting, providing a balance of fuel efficiency, maneuverability, and reliability. Manual Purpose: Essential resource for all maintenance, repair, and diagnostic needs for the Yamaha YJ125, ensuring longevity and optimal performance. 📋 Manual Details Coverage Areas Years Covered: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Page Count Estimated Pages: Hundreds (exact count varies, but substantial) Manual Type Type: Workshop Service Repair Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine Systems: Engine disassembly, assembly, inspection, tuning, lubrication, cooling, fuel, ignition, exhaust, starting, charging Transmission Drivetrain: Transmission operation, inspection, repair, final drive, clutch Chassis Suspension: Frame, front fork, rear shock absorber, swingarm, wheel bearings, steering Braking System: Brake system maintenance, inspection, repair, bleeding, component replacement (discs, pads, calipers, master cylinders) Electrical System: Wiring diagrams, battery, charging system (alternator/stator, rectifier/regulator), ignition system, lighting, instrumentation, starter motor Fuel System: Carburetor disassembly, cleaning, adjustment, fuel pump, fuel tank, fuel lines Body And Trim: Body panel removal/installation, seat, fairings, fenders, trim pieces Procedures Included Maintenance Procedures: Routine maintenance, oil changes, filter replacements, spark plug service, chain adjustment, brake pad inspection/replacement, tire pressure checks Troubleshooting Guides: Systematic diagnostics for common and uncommon issues, fault finding charts Repair Procedures: Step-by-step instructions for component disassembly, repair, and reassembly Overhaul Procedures: Detailed instructions for engine and transmission overhauls Wiring Diagrams: Comprehensive electrical schematics for all systems Technical Depth Depth Level: Comprehensive factory-level detail, suitable for professional technicians and experienced DIY enthusiasts 📊 Manual Specifications File Format File Type: Portable Document Format (PDF) Print Quality Quality: High-resolution scans of original factory documentation, ensuring clarity of text and diagrams Binding Type Binding: N/A (Digital Download) Paper Type Paper: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Four-stroke, air-cooled, SOHC Displacement: Approximately 125cc (Specific bore and stroke figures detailed in manual) Bore X Stroke: Refer to manual for precise dimensions Compression Ratio: Refer to manual for specific ratio Performance Horsepower: Typically in the 8-10 HP range (exact figures vary by market and tuning) Torque: Torque figures available in manual for optimal tuning Fuel System Carburetor Type: CV (Constant Velocity) carburetor, specific model detailed in manual (e.g., Mikuni VM series) Fuel Type: Unleaded gasoline Fuel Capacity: Approximately 5-6 Liters (specific capacity detailed in manual) 🔧 Transmission Standard Transmission Type: Automatic CVT (Continuously Variable Transmission) Drive Type: Belt drive to rear wheel Features Clutch Type: Automatic centrifugal clutch 📐 Dimensions Exterior Overall Length: Refer to manual for exact dimensions Overall Width: Refer to manual for exact dimensions Overall Height: Refer to manual for exact dimensions Weights Dry Weight: Approx. 100-110 kg (Specific figures in manual) Curb Weight: Refer to manual for precise curb weight 🛡️ Safety Features Ratings Safety Standards: Complies with applicable safety regulations for its class in various markets. Specific certifications not typically detailed in service manuals but implicit in design. Active Features Braking System: Disc front brake, drum rear brake (common configuration; check manual for variations). ABS typically not present on this model. Passive Features Lighting: Headlight, taillight, brake light, turn signals for visibility. 💡 Technology Features Infotainment Instrument Cluster: Analog speedometer, fuel gauge, odometer, trip meter, indicator lights (turn signals, oil, high beam). Specific cluster design may vary. Driver Assistance ABS: Anti-lock Braking System (ABS) is typically not a feature on this model. Connectivity Charging Ports: 12V accessory socket (optional or standard depending on market/trim) for charging devices is possible, but not standard on all models. Manual may show...