This manual covers the FL 912, B/FL 913/C, F3 - 6L 912, F3/4/6L 913, BF4/6L 913, and BF6L 913C engine models. These engines are designed for robust performance and reliability, reflecting a commitment to quality engineering. This comprehensive guide is intended to provide users with detailed information to ensure optimal operation and longevity of these power units. The purpose of this manual is to serve as an authoritative resource for maintenance, repair, and technical understanding of the specified engine models. It includes essential sections on technical data, component repair, disassembly and reassembly procedures, and necessary tools. By providing clear instructions and detailed illustrations, this manual aims to assist owners, mechanics, and technicians in effectively maintaining and servicing their engines.