This manual covers the 1979 Yamaha XS650SF, a variant of the iconic XS650 line that debuted in 1970. Known for its characterful parallel-twin engine, the XS650 series represented Yamaha's entry into large-displacement motorcycles, offering a blend of British twin aesthetics with reliable Japanese engineering. The XS650SF, or Special, variant specifically catered to the custom and cruiser market with distinctive styling. This particular model, identified by chassis code XS650SF and engine code 650-2F, features a 653 cc air-cooled parallel-twin engine with overhead valve configuration, dual Mikuni carburetors, and a 5-speed transmission, delivering approximately 50-53 horsepower. This comprehensive Workshop Service Repair Manual in English provides detailed, step-by-step instructions for the maintenance, diagnostics, and repair of all major mechanical, electrical, and structural systems of the 1979 Yamaha XS650SF. It includes extensive coverage of the fuel system, engine top end, clutch, lubrication system, crankshaft, transmission, wheels, tires, brakes, suspension, steering, frame, and the complete electrical system, supported by hundreds of photos and illustrations. The manual is designed to assist both do-it-yourself enthusiasts and professional mechanics in keeping the motorcycle in optimal working condition, offering troubleshooting guides and critical safety information. 🏷️ Basic Information Identification Make: Yamaha Model: XS650SF Model Variant: XS650-2F Year: 1979 Codes Chassis Code: XS650SF Engine Code: 650-2F 👋 Introduction Market Position Target Audience: Do-it-yourself enthusiasts and professional mechanics seeking comprehensive repair and maintenance guidance. Key Features Value Proposition: Inexpensive way to keep the vehicle working properly by providing expert-level repair and service information. Convenience: Instant download, printable pages, no shipping costs or waiting time for physical delivery. 📋 Manual Details Coverage Areas General Information: Included Fuel System: Included Cooling System: Included Engine Top End: Included Clutch: Included Engine Lubrication System: Included Engine Removal Installation: Included Crankshaft Transmission: Included Wheels Tires: Included Final Drive: Included Brakes: Included Suspension: Included Steering: Included Frame: Included Electrical System: Included Appendix: Included Page Count Estimated Pages: Hundreds of pages (specific count not provided, but indicative of a comprehensive manual) Manual Type Type: Workshop Service Repair Manual Language Language: English Format File Format: PDF 📖 Manual Coverage Systems Covered All Systems: Covers all major mechanical, electrical, and structural systems of the motorcycle. Procedures Included Maintenance And Repair: Detailed step-by-step instructions for maintenance, diagnostics, and repair procedures. Troubleshooting: Includes troubleshooting guides and procedures for diagnosing and resolving common and uncommon issues. Disassembly Assembly: Covers complete disassembly and reassembly of the motorcycle and its components. Electrical System Repair: Includes comprehensive procedures for diagnosing and repairing the entire electrical system, from battery and charging components to lighting, ignition, and starting circuits, supported by detailed wiring diagrams. Technical Depth Depth: Comprehensive, suitable for both do-it-yourself owners and experienced mechanics. Accuracy And Completeness: This manual is presented as the COMPLETE official full factory service repair manual, ensuring a high degree of accuracy and completeness for all repair and maintenance tasks. Illustrations And Diagrams Visual Aids: Hundreds of photos, illustrations, drawings, and enlarged insets for detailed part identification and procedure guidance. Technical Information Notes Cautions Warnings: Includes critical notes, cautions, and warnings throughout each chapter to pinpoint important information. Electrical Diagrams: Detailed wiring diagrams integrated with troubleshooting and electrical service procedures. 📊 Manual Specifications File Format Compatibility: Compatible with all PC-based Windows operating systems and Mac. Print Quality Printability: Printable without any restriction, either entire manual or specific pages. Delivery Method Delivery: Digital download, link provided on checkout page after payment. Requirements Software Requirement: Adobe PDF Reader Binding Type Binding: N/A (Digital PDF download) Paper Type Paper Quality: N/A (Digital PDF download) ⚙️ Engine Specifications Primary Engine Configuration: Parallel-Twin (Vertical Twin) Displacement: 653 cc Bore X Stroke: 73.0 mm x 77.5 mm (Typical for XS650, specific for 1979 model confirmed in manual) Compression Ratio: 8.2:1 (Typical for XS650, specific for 1979 model confirmed in manual) Valve Train: Overhead Valve (OHV), pushrod actuated with two valves per cylinder (one intake, one exhaust). Ignition System: CDI (Capacitor Discharge Ignition) with dual spark plugs per cylinder for improved combustion. (Details on ignition timing and components in manual) Performance Horsepower: Approx. 50-53 HP (Estimated, actual figure varies by tuning and specific model year, details in manual) Torque: Approx. 36-38 lb-ft (Estimated, actual figure varies by tuning and specific model year, details in manual) Fuel System Carburetion: Dual Mikuni VM34SC Carburetors (Typical for XS650SF, details in manual) Fuel Capacity: 17 Liters (4.5 US gal) (Typical for XS650, details in manual) Cooling System Method: Air-cooled 🔧 Transmission Standard Type: 5-speed constant mesh Features Drive System: O-ring sealed chain drive Fluid Specifications Transmission Oil Type: Yamalube 4 (or equivalent API SE, SF, SG, SH, SJ, SK, SL, SM, SN, SO) SAE 20W-40 or SAE 10W-40 (refer to manual for exact specifications) Fluid Capacities Transmission Oil Capacity: Approx. 2.0 Liters (for gearbox and primary drive, specific amount for lubrication and final drive covered in manual) 📐 Dimensions Weights Dry Weight: Approx....