This Engine Repair Manual covers MerCruiser GM 454/502 7.4/8.2 marine engines from the 1998-2001 model years, specifically the Gen. VI engine family. These V8 engines, available in 7.4L (454 cid) and 8.2L (502 cid) displacements, feature Electronic Fuel Injection (MPI) and are designed for marine applications. The manual addresses both seawater-cooled and closed-cooled systems and provides comprehensive information for sterndrive (Bravo, Blackhawk) and inboard (Velvet Drive, Hurth, Walter) transmissions. This comprehensive English-language manual is designed to assist owners, mechanics, and technicians in maintaining and repairing these MerCruiser engines and associated transmissions. It details essential maintenance procedures, overhaul processes, troubleshooting guides, and repair techniques. The manual includes part and wiring diagrams, and offers specific guidance for trouble code diagnostics on 454/502 Mag MPI, 8.2L MPI, and 7.4L MPI models, ensuring effective upkeep and performance.