This manual covers the Volvo B21 engine, an internal combustion engine known for its robust engineering and reliability. This inline 4-cylinder engine, with a displacement of 2.1 liters, was commonly fitted to Volvo 200 Series vehicles and early 700 Series models. It features a liquid-cooled system, an Overhead Valve (OHV) valvetrain with pushrods, and a distributor and coil ignition system. Depending on the specific application and tuning, the engine typically produced between approximately 90-120 horsepower and 130-150 lb-ft of torque, utilizing either a carburetor or fuel injection system. This Service Repair Manual provides comprehensive guidance for the maintenance and repair of the Volvo B21 engine. It details essential procedures, technical specifications, and troubleshooting information necessary for owners, mechanics, and technicians. Coverage includes recommended lubrication types and capacities, oil change and tune-up intervals, and information on associated transmission types. The professional quality, in-depth content ensures that users can effectively maintain the engine's performance and longevity.