This workshop service manual covers the Mercury Mariner 225/250 HP EFI outboard models from the EFI Era. Engineered for reliability and performance, these powerful outboard engines are designed for a variety of marine applications. Their advanced Electronic Fuel Injection (EFI) system ensures efficient operation and optimal power output, delivering a dependable experience on the water. This comprehensive manual provides detailed information essential for the maintenance, repair, and troubleshooting of your Mercury Mariner outboard. It includes procedures for routine servicing, diagnostic guidance for common issues such as starting problems, fuel delivery, ignition, and cooling systems, as well as technical specifications and safety recommendations. This resource is invaluable for owners, technicians, and mechanics seeking to maintain the optimal performance and longevity of their Mercury Mariner 225/250 HP EFI engines.