This manual covers the Z250 and KZ305 models, including the KZ305 CSR variant, produced between 1979 and 1982. These motorcycles, originating from Japan, were designed as entry-level to mid-range performance machines, offering a blend of sporty aesthetics and accessible power, propelled by an air-cooled, inline-twin, 4-stroke engine with DOHC. The legacy is built on engineering quality and reliability, and these models contributed to that reputation by providing a balanced riding experience with features like a 6-speed transmission and a chain drive. The Z250 and KZ305 series, with their characteristic styling, represented a significant offering in their class during their production years. This comprehensive Service Repair Workshop Manual in English provides detailed guidance for all aspects of maintenance, repair, and troubleshooting for your Z250 or KZ305. It covers everything from routine checks and lubrication to in-depth engine work, fuel system servicing, electrical diagnostics, and suspension adjustments. With step-by-step instructions, clear diagrams, and illustrations, this manual empowers owners and technicians to maintain their vehicles effectively, ensuring longevity and optimal performance. It includes factory specifications, diagnostic procedures, and troubleshooting charts for common issues, making it an essential resource for anyone looking to keep these classic motorcycles in top condition.