🏷️ Basic Information Identification Make: Yamaha Model: DT125R Year: 1987, 1988 Codes Vin Prefix: 430, 4GC 👋 Introduction Market Position Market Position: The Yamaha DT125R was a popular dual-sport motorcycle, known for its off-road capability and reliable two-stroke engine. This manual targets owners and independent repair shops looking to maintain and repair these specific models. Competitive Analysis Competitive Analysis: Competed with other 125cc dual-sport and enduro motorcycles of its era, offering a good balance of performance and durability. This manual is essential for those who value keeping this classic model in optimal condition. Key Features Key Features: Enables self-repair, provides detailed troubleshooting, covers all major systems, essential for DIY maintenance and comprehensive servicing. 📋 Manual Details Coverage Areas Coverage Areas: General Information, Specifications, Periodic Maintenance and Adjustment, Engine, Cooling System, Electrical System, Chassis, Carburetors, Troubleshooting, Index Page Count Page Count: Not specified, but comprehensive workshop manual implies hundreds of pages. Manual Type Manual Type: Workshop Service Repair Manual Language Language: English Format Format: PDF Completeness Completeness: Complete workshop manual for the specified years and model variant. 📖 Manual Coverage Systems Covered Systems Covered: Engine mechanicals (cylinder, piston, crankshaft, gearbox), Fuel system (carburetor tuning, jetting), Ignition system, Lubrication, Cooling system (liquid cooling), Electrical system (wiring diagrams, lighting, charging system), Chassis (frame, suspension, steering, brakes), Wheels and tires, Bodywork, Troubleshooting common faults. Chassis Components: Frame, front forks, rear shock absorber, steering system, swingarm, wheel hubs, spokes, tires, brakes (front and rear discs), controls, footpegs, seat. Electrical System Components: Ignition coil, CDI unit, lighting (headlight, taillight, indicators), battery, charging system (stator, rectifier/regulator), horn, starter motor (if applicable), wiring harness, fuses. Procedures Included Procedures Included: Engine disassembly, inspection, and reassembly; Carburetor cleaning, adjustment, and synchronization; Valve clearance adjustment (if applicable); Ignition timing checks; Cooling system flushing and filling; Electrical component testing and replacement; Brake system bleeding and component replacement; Suspension fork servicing; Chain and sprockets maintenance; Wheel bearing replacement; Troubleshooting diagnostic procedures. Engine Rebuild Procedures: Detailed steps for cylinder head removal, piston replacement, ring installation, crankshaft bearing replacement, gearbox disassembly and reassembly, clutch service, and power valve maintenance (if applicable). Suspension Servicing: Front fork oil change, seal replacement, spring inspection. Rear shock absorber inspection and adjustment (preload). Technical Depth Technical Depth: Comprehensive. Covers detailed repair procedures, diagnostic flowcharts, specifications for torque values, clearances, and measurements. Suitable for both amateur mechanics and professional technicians. Specifications Included: Torque specifications for all major fasteners, engine clearances (e.g., piston-to-cylinder wall, ring gap), suspension settings, electrical resistance values, carburetor jet sizes and settings. Troubleshooting Troubleshooting Depth: Detailed diagnostic flowcharts and symptom-based troubleshooting guides for common mechanical, electrical, and fuel system problems. 📊 Manual Specifications File Format File Format: PDF Print Quality Print Quality: High-resolution digital scan suitable for clear printing of all diagrams and text. Binding Type Binding Type: Digital (PDF) Paper Type Paper Type: Digital (PDF) - Printable Compatibility Compatibility: Windows, Mac ⚙️ Engine Specifications Primary Engine Primary Engine: Liquid-cooled, 2-stroke, reed valve induction Displacement: 123 cc Bore X Stroke: 56.5 mm x 49.8 mm Compression Ratio: 7.2:1 (approx.) Performance Horsepower: Approx. 20-23 HP (varies by market and tune) Torque: Approx. 16-18 Nm Fuel System Fuel System: Carburetor Carburetor Model: Mikuni VM26SS (typical) Fuel Type: Unleaded gasoline, 91-95 RON Fuel Mixture: Pre-mix or Auto-lube system Lubrication Lubrication System: Premix or Autolube (oil injection system, detailed in manual). Cooling System Cooling System Type: Liquid-cooled Coolant Capacity: Approximately 0.8 liters (refer to manual for exact specification). 🔧 Transmission Standard Transmission Type: 6-speed constant mesh Clutch Type: Wet, multiple-disc Final Drive: Chain drive Features Gear Ratios: Detailed in manual, crucial for engine tuning and performance optimization. 📐 Dimensions Exterior Length: Approx. 2165 mm Width: Approx. 830 mm Height: Approx. 1240 mm Wheelbase: Approx. 1410 mm Ground Clearance: Approx. 310 mm Seat Height: Approx. 875 mm Weights Dry Weight: Approx. 116 kg Wet Weight: Approx. 125 kg (with fluids) Fuel Tank Capacity: 10 liters Payload Capacity: Not specified, typically rider + limited cargo for dual-sport. 🛡️ Safety Features Active Features Active Features: Disc brakes front and rear, adjustable suspension, responsive handling. Passive Features Passive Features: Durable frame construction, protective bodywork. Ratings Safety Ratings: N/A (motorcycle safety ratings of this era are not standardized like automobiles). 💡 Technology Features Infotainment Infotainment: Not applicable; this is a mechanical and electrical service manual for a 1980s motorcycle. Driver Assistance Driver Assistance: Not applicable. Connectivity Connectivity: Not applicable. 🔧 Maintenance Service Intervals Service Intervals: Detailed within the manual, typically including: Oil changes (if applicable), spark plug checks/replacement, air filter cleaning/replacement, chain lubrication/adjustment, brake fluid checks, coolant checks, and general inspection points at regular mileage or time intervals. Fluid Specifications Fluid Specifications: Manual specifies coolant type (e.g., ethylene glycol-based), transmission oil grade (e.g., Yamalube 10W-30 or equivalent API SE/SF), brake fluid type (DOT 3 or DOT 4), and 2-stroke oil for the Autolube system (e.g., Yamalube 2-Stroke...