🏷️ Basic Information Identification Make: Yamaha Model: XS400 Years Covered: 1977, 1978, 1979, 1980, 1981, 1982 Codes Vehicle Segment: Mid-size Motorcycle 👋 Introduction Market Position Purpose For Owner: Empowers owners to perform their own repairs and maintenance, saving money and increasing knowledge. Competitive Analysis Value Proposition: Provides essential information for DIY repairs, reducing reliance on expensive dealership services. Key Features Ease Of Use: Step-by-step instructions designed for ease of understanding and execution. Comprehensiveness: Covers all service and repair jobs, including routine maintenance. Accessibility: Instant download means immediate access to critical repair information. 📋 Manual Details Coverage Areas Manual Type: Workshop Service Manual (WSM) / Repair Manual Language: English Format: PDF Download Print Quality: Full Printable Delivery Method: Instant Download Software Requirements: Adobe PDF Reader Compatibility: All Versions of Windows & Mac 📖 Manual Coverage Systems Covered Engine: Complete engine overhaul, disassembly, assembly, tuning, and troubleshooting Fuel System: Carburetor identification, adjustment, cleaning, and overhaul; fuel pump (if applicable); fuel tank and lines Ignition System: CDI unit, ignition coils, spark plugs, timing adjustment Transmission Drivetrain: Gearbox disassembly, assembly, clutch operation, final drive inspection and maintenance Electrical System: Comprehensive wiring diagrams, lighting, charging system (stator, rectifier/regulator), battery, starter motor, switches Suspension: Front fork (oil, seals, springs), rear shock absorbers (adjustment, replacement), linkage maintenance Brakes: Front and rear brake systems (disc and/or drum), master cylinder, calipers, brake pads/shoes, fluid replacement, bleeding procedures Cooling System: Air cooling system inspection and maintenance Frame Chassis: Frame inspection, steering head bearing service, swingarm maintenance Bodywork Trim: Fairings, tank, seat, fenders, mounting points Procedures Included Routine Maintenance: Oil changes, filter replacements, chain adjustment, spark plug checks, tire pressure Troubleshooting: Diagnostic guides for common problems, symptoms, and remedies Repair Procedures: Step-by-step instructions for component replacement and repair Overhaul Procedures: Detailed guides for complete engine, transmission, and carburetor overhauls Inspection: Visual inspection guidelines for all major components Adjustment: Carburetor synchronization, valve clearance, chain tension, brake levers Technical Depth Depth Of Coverage: In-depth, professional quality coverage for both novice and experienced mechanics Diagnostic Tools: Information on required tools and diagnostic techniques Specifications Data: Torque specifications, clearances, fluid capacities, electrical values Illustrations: Includes pictures and diagrams for visual guidance Wiring Diagrams: Comprehensive and detailed wiring schematics 📊 Manual Specifications File Format File Type: PDF Print Quality Printability: All pages are printable Binding Type Binding: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, 4-stroke, DOHC, Parallel-twin Displacement: 392 cc (approximately, specific variants may vary slightly) Bore X Stroke: 69.0 mm x 51.8 mm (typical for early models) Compression Ratio: 9.7:1 (typical) Performance Horsepower: Approx. 33-36 HP @ 7500-8000 RPM (varies by year and tune) Torque: Approx. 23-25 lb-ft @ 6000-6500 RPM (varies by year and tune) Fuel System Carburetors: Dual Mikuni VM34 or similar 34mm constant velocity carburetors Fuel Capacity: Approx. 17 Liters (4.5 US gal) Fuel Type: Unleaded Gasoline (Octane rating as specified in manual) Lubrication Oil Type: Yamalube 4-stroke motorcycle oil or equivalent (e.g., SAE 20W-40 or 10W-40 depending on climate) Oil Capacity: Approx. 2.4 Liters (2.5 US qt) with filter change Ignition Ignition System: CDI (Capacitor Discharge Ignition) Spark Plugs: NGK D8EA or equivalent (specific plug type to be confirmed in manual) 🔧 Transmission Standard Transmission Type: 5-speed constant mesh Clutch Type: Wet multi-plate Features Final Drive: Chain drive Transmission Oil: Yamalube Hypoid Gear Oil (GL-5) or equivalent (specific viscosity recommended) 📐 Dimensions Exterior Wheelbase: Approx. 1400-1420 mm (55.1-55.9 in) Weights Dry Weight: Approx. 170-180 kg (375-397 lbs) 🛡️ Safety Features Ratings Safety Features: Standard motorcycle safety features; manual covers brake system maintenance for optimal performance. 💡 Technology Features Infotainment Infotainment Systems: N/A (Classic motorcycle, no electronic infotainment systems). Driver Assistance Driver Assistance Features: N/A (Classic motorcycle, no electronic driver assistance). Connectivity Connectivity Options: N/A (Classic motorcycle, no electronic connectivity). 🔧 Maintenance Service Intervals Engine Oil Change: Every 3,000-4,000 km (1,800-2,500 miles) or 6 months, whichever comes first. Valve Clearance Check: Every 6,000-8,000 km (3,700-5,000 miles) or annually. Spark Plug Replacement: Every 10,000-12,000 km (6,000-7,500 miles) or as per manual recommendation. Chain Lubrication Adjustment: Every 500-1,000 km (300-600 miles). Fluid Specifications Brake Fluid Type: DOT 3 or DOT 4 brake fluid (refer to specific manual for exact type and specification). Known Issues Common Wear Items: Carburetor synchronization drift, intake manifold cracking, clutch wear, electrical component reliability over time. Carburetor Issues: Degradation of rubber diaphragms and seals in carburetors, leading to tuning difficulties. Electrical Aging: Aging wiring insulation, corroded connectors, and potential failure of the rectifier/regulator unit. 📚 Vehicle History Brand Heritage Yamaha Legacy: Yamaha Motor Company, known for its long history in motorcycle manufacturing and innovation, dating back to the 1950s. Model Evolution Xs400 Context: The XS400 was part of Yamaha's line of parallel-twin motorcycles, offering a balance of performance, styling, and reliability for its era. It was often marketed as...