The 1999 Yamaha TW125 is a lightweight dual-sport motorcycle renowned for its distinctive fat tires, which provide exceptional traction and a comfortable ride across various terrains. Designed for trail riding and light adventure, this model embodies a commitment to simplicity, ease of use, and robust construction. Its air-cooled, 124cc engine, coupled with a 5-speed transmission and a durable steel cradle frame, makes it a capable and reliable machine. The TW125 offers a unique blend of off-road prowess and user-friendly operation, positioning it as a practical choice for enthusiasts and everyday riders alike. This workshop service manual provides comprehensive guidance for the maintenance and repair of your 1999 Yamaha TW125. It covers all essential systems, including detailed procedures for engine overhaul, transmission service, fuel and ignition system tuning, and electrical diagnostics. The manual also includes information on suspension and braking systems, chassis maintenance, and bodywork. With its in-depth troubleshooting guides, routine maintenance schedules, and technical specifications, this manual is an indispensable resource for professional technicians and DIY owners aiming to keep their TW125 in optimal condition. 🏷️ Basic Information Identification Make: Yamaha Model: TW125 Year: 1999 Market Segment: Dual-Sport/Trail Motorcycle Codes Chassis Code: Likely 5FL or similar Yamaha internal code 👋 Introduction Market Position Vehicle Class: Lightweight dual-sport motorcycle known for its simplicity, ease of use, and off-road capability, particularly favored for trail riding and light adventure. Competitive Analysis Competitors: Competed with other 125cc dual-sport motorcycles from manufacturers like Honda (e.g., XR125), Suzuki (e.g., DR125), and Kawasaki (e.g., KLR125) of the era. Key Features Unique Selling Points: Fat tires (hence 'TW'), which provide exceptional traction and comfort on varied terrain, simple air-cooled engine, robust construction. Manual Value Proposition Target Audience: Professional motorcycle technicians, independent repair shops, and ambitious DIY owners seeking to maintain or restore their 1999 Yamaha TW125. 📋 Manual Details Coverage Areas Geographical Coverage: Global (likely focused on markets where TW125 was officially sold, e.g., Europe, Japan) Page Count Estimated Page Count: Hundreds of pages (as stated in product description) Manual Type Manual Type: Workshop Service Manual / Repair Manual Language Language: English Format Digital Format: PDF Download 📖 Manual Coverage Systems Covered Engine: Detailed overhaul, tuning, troubleshooting of the 125cc engine. Transmission: Clutch, gearbox, final drive maintenance and repair. Fuel System: Carburetor (likely Mikuni VM series), fuel lines, fuel tank inspection and service. Ignition System: CDI unit, ignition coil, spark plug, timing checks. Electrical System: Wiring diagrams, lighting, battery, charging system (stator, regulator/rectifier), starting system. Suspension: Front telescopic forks (oil change, seal replacement) and rear monoshock absorber (adjustment, overhaul). Braking System: Front and rear drum or disc brakes (depending on specific market variant), hydraulic components, pad/shoe replacement, fluid. Chassis And Frame: Frame inspection, steering head bearings, swingarm bearings. Bodywork And Trim: Fenders, seat, fuel tank removal and installation, minor body panel repairs. Procedures Included Routine Maintenance: Oil changes, filter replacements, chain adjustment, lubrication, tire pressure checks. Troubleshooting: Systematic diagnostic procedures for common and uncommon faults. Engine Rebuild: Complete engine disassembly, inspection, part replacement, and reassembly. Carburetor Overhaul: Jet cleaning, float level adjustment, mixture screw settings. Electrical Diagnostics: Using wiring diagrams to trace faults, testing components. Suspension Service: Fork seal replacement, fork oil viscosity and level specifications. Brake System Maintenance: Bleeding procedures, inspection of brake components. Technical Depth Depth Of Information: Comprehensive, suitable for professional technicians and advanced DIY mechanics. Diagnostic Capability: Advanced diagnostic flowcharts and troubleshooting trees. Rebuild Information: Detailed overhaul procedures for major components including engine, transmission, and suspension. 📊 Manual Specifications File Format File Format: PDF Print Quality Printability: Full Printable Zoom Capability: YES Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) Software Requirements PDF Reader: Adobe PDF Reader Compression Utility: WinRAR Compatibility Operating Systems: All Versions of Windows & Mac ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, four-stroke, SOHC, single-cylinder Displacement: 124 cc Bore X Stroke: 54 mm x 54 mm (Typical for this era Yamaha 125cc) Compression Ratio: Likely around 9.5:1 to 10.5:1 Performance Horsepower: Approximately 10-12 HP (actual figures vary by market and tuning) Torque: Approximately 9-10 Nm (actual figures vary by market and tuning) Fuel System Carburetor Type: Mikuni VM Series (e.g., VM20 or VM22), single carburetor Fuel Capacity: Approximately 9 Liters (including reserve) Lubrication Oil Type: API SE, SF, SG, SH or higher, SAE 10W-40 recommended (check manual for exact specification) Oil Capacity: Approximately 1.0-1.2 Liters (with oil filter change) 🔧 Transmission Standard Transmission Type: 5-speed constant mesh Clutch Type: Wet, multiple-disc Final Drive: Chain drive Features Gear Ratios: Specific ratios detailed in the manual, designed for tractable off-road power delivery. Transmission Oil Type: Yamalube 4 (or equivalent) SAE 10W-40, API SE, SF, SG, SH or higher 📐 Dimensions Exterior Overall Length: Approx. 2055 mm Overall Width: Approx. 820 mm Overall Height: Approx. 1115 mm Seat Height: Approx. 800 mm Weights Dry Weight: Approx....