This factory repair manual covers the Mercury 30/40 Hp 4-Stroke Outboard models manufactured between 1999 and 2010, identified by starting serial number 0G760300. These robust 4-stroke engines, available in 30 hp and 40 hp configurations, are engineered for reliability and performance. This manual provides comprehensive information to ensure optimal operation and longevity of your Mercury outboard. The purpose of this manual is to serve as a complete guide for maintenance, repair, and troubleshooting of your Mercury 30/40 Hp 4-Stroke Outboard. It details step-by-step procedures for disassembling, cleaning, inspecting, assembling, testing, and installing all components, including the powerhead, cylinder head, crankcase, midsection, starter, fuel system, electrical system, and transmission. With clear instructions and color wiring diagrams, this manual is an essential resource for owners and technicians alike to maintain and service the engine effectively.