This workshop service repair manual provides comprehensive guidance for the XS400 Standard, covering production years from 1977 through 1982. The XS400, a popular mid-displacement parallel-twin motorcycle, is celebrated for its engineering quality, reliability, and balanced performance, making it a favored choice for both daily commuting and extended rides. This manual details the air-cooled, 4-stroke, DOHC parallel-twin engine, known for its smooth power delivery and durability, and covers all standard variants of this iconic model. This manual is meticulously designed to assist owners, mechanics, and technicians in maintaining and repairing their XS400. It encompasses a vast range of topics, including detailed disassembly and reassembly procedures, engine tuning, carburetor adjustments, electrical system diagnostics, brake system maintenance, suspension overhauls, and troubleshooting common issues. With step-by-step instructions, detailed illustrations, and comprehensive wiring diagrams, this English-language manual offers the in-depth information necessary for both routine maintenance and complex repairs, ensuring the longevity and optimal performance of your motorcycle.