The XS400, produced from 1977 to 1982, represents a significant entry in the mid-size parallel-twin motorcycle market. This first-generation model, encompassing variants like the XS400-1 and XS400-2, is characterized by its air-cooled, four-stroke, DOHC parallel-twin engine, typically displacing around 392 cc. Known for its balance of performance and usability, the XS400 was designed to offer an accessible riding experience, complemented by its reliable engineering and the esteemed heritage of its manufacturer. Its design typically features dual front disc brakes on later models and an enclosed chain drive, contributing to its practical appeal for both commuting and recreational riding. This comprehensive Service Repair Workshop Manual provides essential information for the maintenance and repair of the XS400 models from 1977 through 1982. It covers a wide array of systems, including detailed procedures for engine overhaul, carburetor tuning, transmission, fuel system, electrical systems, brakes, suspension, and bodywork. The manual facilitates routine maintenance, periodic checks, and complex troubleshooting, offering systematic diagnostic procedures and clear instructions for component rebuilds and adjustments. With detailed diagrams, illustrations, exploded views, and complete electrical wiring diagrams, this English-language manual is an indispensable resource for XS400 owners, independent repair shops, and DIY enthusiasts seeking to maintain their motorcycles effectively and economically. 🏷️ Basic Information Identification Make: Yamaha Model: XS400 Generation Model Generation: First Generation (XS400-1, XS400-2) Codes Chassis Codes: Often referred to by engine type/variant codes, e.g., 2H7, 4G5 👋 Introduction Market Position Target Audience: Yamaha XS400 owners, independent repair shops, DIY enthusiasts Competitive Analysis Value Proposition: Provides dealership-level repair and maintenance information at a fraction of the cost Key Features Accuracy Conciseness: Accurate, clear, and concise text combined with detailed illustrations Vehicle Specificity: Vehicle-specific, not generic repair information Cost Savings: Enables significant cost savings on maintenance and repairs 📋 Manual Details Coverage Areas Covered Years: 1977, 1978, 1979, 1980, 1981, 1982 Page Count Estimated Page Count: Detailed PDF, estimated to be comprehensive, likely 300+ pages Manual Type Type: Service Repair Workshop Manual Language Language: English Format File Format: PDF 📖 Manual Coverage Systems Covered Engine: Complete engine overhaul, diagnostics, carburetor tuning, valve adjustment Transmission: Gearbox disassembly, inspection, assembly, clutch operation Drive System: Drive chain inspection, adjustment, sprocket replacement, lubrication Fuel System: Carburetor service, fuel tank, fuel lines, fuel pump (if applicable) Cooling System: Coolant specifications, radiator service, thermostat Electrical System: Ignition system, lighting, battery, charging system, starter motor, wiring diagrams Brakes: Front and rear brake systems, hydraulic components, pad/shoe replacement Suspension: Front forks, rear shock absorbers, adjustments, rebuild procedures Steering: Handlebar, steering head bearings, lubrication, adjustments Bodywork: Panel removal, seat, fenders, trim components Intake Exhaust: Air filter service, exhaust system inspection and maintenance Procedures Included Routine Maintenance: Oil changes, filter replacements, chain lubrication, tire pressure checks Periodic Checks: Valve clearance, spark plug condition, brake fluid levels Troubleshooting: Systematic diagnostic procedures for common and advanced issues Rebuilds: Engine, carburetor, and suspension component rebuilds Adjustments: Carburetor synchronization, idle speed, clutch and brake levers Technical Depth Depth: Comprehensive from basic owner maintenance to full engine and electrical system overhauls Diagrams Illustrations: Includes detailed diagrams, illustrations, and exploded views for clarity Wiring Schematics: Complete electrical wiring diagrams for troubleshooting and repair 📊 Manual Specifications File Format Compatibility: Compatible with all versions of Windows and Mac Print Quality Printability: All pages are printable Binding Type Binding: N/A (Digital PDF format) Paper Type Paper Type: N/A (Digital PDF format) Requirements Software Requirements: Adobe PDF Reader ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, four-stroke, DOHC parallel-twin Displacement: 392 cc (approximately) Bore X Stroke: Specifications vary slightly by sub-model, typically around 64.0 mm x 62.0 mm Compression Ratio: Typically around 8.8:1 to 9.2:1 Performance Horsepower: Approximately 33-36 hp at 7,500-8,000 rpm Torque: Approximately 23-25 lb-ft at 6,000-6,500 rpm Fuel System Carburetion: Dual Mikuni VM34-type carburetors (or similar VM series) Fuel Capacity: Approx. 12-14 liters (3.2-3.7 US gallons) 🔧 Transmission Standard Transmission Type: Constant mesh, 5-speed sequential manual Optional Optional Transmission: N/A Features Clutch Type: Wet, multi-plate, diaphragm spring Final Drive: Enclosed chain drive 📐 Dimensions Exterior Length: Approximately 2,100-2,200 mm (varies by model year) Width: Approximately 750-800 mm Height: Approximately 1,100-1,150 mm Weights Dry Weight: Approximately 170-185 kg Wet Weight: Approximately 185-200 kg 🛡️ Safety Features Ratings Safety Ratings: N/A (Motorcycle safety is assessed differently than cars) Active Features Braking System: Dual front disc brakes (on later models), single rear disc or drum brake Passive Features Lighting: Headlight, taillight, turn signals, brake light 💡 Technology Features Infotainment Infotainment System: N/A (Analog instrumentation typical for the era) Driver Assistance Driver Assistance Features: N/A Connectivity Connectivity Features: N/A 🔧 Maintenance Service Intervals Oil Change Interval: Typically every 2,000-3,000 miles or 6 months (refer to manual for exact specification) Valve Adjustment Interval: Typically every 4,000-6,000 miles Chain Lubrication Interval: Every 500-1,000 miles and after washing or riding in wet conditions Fluid Specifications Engine Oil Type: Yamalube 4 (or equivalent...