This manual covers the DT125R, a dual-sport motorcycle produced for the 1987 and 1988 model years. Known for its robust 123cc two-stroke, liquid-cooled engine and agile chassis, the DT125R offers a blend of off-road capability and street legality, reflecting a heritage in performance-oriented dual-sport motorcycles. Its design emphasizes reliability and a straightforward mechanical approach, making it a popular choice for riders seeking adventure and versatility. This comprehensive service and repair manual provides detailed information for maintaining and repairing the DT125R. It covers a wide array of systems, including the engine, transmission, fuel, ignition, electrical systems, chassis, suspension, and brakes. The manual includes routine maintenance procedures, advanced troubleshooting guides, detailed specifications, and wiring diagrams, all presented with clear illustrations to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of the vehicle. 🏷️ Basic Information Identification Make: Yamaha Model: DT125R Applicable Years: 1987, 1988 Codes Engine Code Range: Likely 1G2/1GE series based on typical Yamaha designations for this era, specific codes require manual confirmation. Chassis Code Range: Likely 1G2/1GE series for the DT125R, specific codes require manual confirmation. 👋 Introduction Market Position Target Audience: Yamaha DT125R owners, mechanics, restorers, and enthusiasts seeking detailed repair and maintenance information. Competitive Analysis Value Proposition: Provides the same in-depth information used by professional technicians, enabling owners to perform complex repairs and maintenance themselves, saving significant costs. Key Features Illustration Quality: Detailed illustrations, drawings, and photos to guide procedures, including enlarged inset views for critical components. Navigability: Numbered table of contents for quick information retrieval and bold figure numbers to match illustrations with instructions. Safety Notes: Includes notes, cautions, and warnings throughout to highlight critical safety and procedural information. 📋 Manual Details Coverage Areas General Coverage: Full Service Repair Specific Systems: Engine, Transmission, Fuel System, Ignition System, Electrical System, Chassis, Suspension, Brakes, Cooling System, Lubrication System, Bodywork, Troubleshooting, Wiring Diagrams. Page Count Estimated Page Count: While not explicitly stated, comprehensive full service repair manuals for this era typically range from 300 to 600+ pages depending on the detail. Manual Type Manual Type: Service and Repair Manual Language Language: English Format File Format: PDF Delivery Method: Instant Download Compatibility: All Windows and Mac versions 📖 Manual Coverage Systems Covered Engine Overhaul: Yes, includes detailed breakdown, assembly, and tuning procedures for the 125cc two-stroke engine. Transmission Service: Yes, covering gearbox, clutch, and shifting mechanism maintenance and repair. Electrical Diagnostics: Yes, with comprehensive wiring diagrams for ignition, lighting, and other electrical components. Suspension And Steering: Yes, including fork and rear shock absorber servicing, along with steering head bearing maintenance. Braking System: Yes, covering hydraulic front disc and rear drum brake system maintenance and component replacement. Procedures Included Routine Maintenance: Yes, including oil changes, chain adjustment, filter cleaning/replacement, spark plug service. Troubleshooting Guide: Yes, detailed diagnostic procedures for common and uncommon issues. Rebuilding And Reconditioning: Yes, designed for full restoration and component rebuilding. Torque Specifications: Yes, essential for proper assembly and component longevity. Technical Depth Diagnostic Capabilities: Advanced, covering electrical circuit tracing and component testing. Repair Scope: Comprehensive, suitable for professional technicians and experienced DIY enthusiasts. 📊 Manual Specifications File Format PDF Quality: High Resolution, fully printable. Print Quality Printability: All pages are printable, allowing for on-the-bench use. Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) Requirements Software Requirements: Adobe PDF Reader, WinRAR (for potential archive extraction). ⚙️ Engine Specifications Primary Engine Engine Type: Two-stroke, liquid-cooled, single-cylinder Displacement: 123 cc (7.5 cubic inches) Bore X Stroke: Typically 56.4 mm x 50.0 mm for this model, but manual confirmation is advised. Compression Ratio: Likely around 7.2:1 or similar for this era of two-stroke, manual confirmation needed. Performance Horsepower Output: Approx. 21-23 hp at 8000 rpm (subject to regional tuning and specific model variant, manual confirmation required). Torque Output: Approx. 19-20 Nm at 7000 rpm (subject to regional tuning and specific model variant, manual confirmation required). Fuel System Carburetor Type: Mikuni VM28SS or similar, with specific jetting and adjustment procedures detailed in the manual. Fuel Type: Unleaded gasoline with a recommended octane rating (e.g., 95 RON) and a proper two-stroke oil mix (typically 50:1 or as specified). 🔧 Transmission Standard Transmission Type: 6-speed constant mesh Features Clutch Type: Wet, multiple disc Final Drive: Chain drive 📐 Dimensions Exterior Overall Length: Varies slightly by model year but typically around 2050-2100 mm. Overall Width: Varies, but typically around 800-830 mm. Overall Height: Varies, but typically around 1160-1180 mm. Weights Dry Weight: Approximately 115-120 kg. Gross Vehicle Weight Rating: Manual will specify, but typically around 250-270 kg. 🛡️ Safety Features Active Features Braking System Front: Hydraulic disc brake Braking System Rear: Drum brake Passive Features Lighting: Headlight, taillight, turn signals (all covered in electrical section). 💡 Technology Features Infotainment Infotainment Systems: N/A - This is a 1980s era motorcycle with no modern infotainment systems. Driver Assistance...