This Service Repair Manual covers the Mercury Mercruiser 350 CID engine models produced from 1998 through 2001. These V8 engines, based on the Small-Block Chevrolet architecture, typically produce between 250-300 horsepower and 300-350 ft-lbs of torque. Featuring fuel injection and electronic ignition, these engines were designed for reliability and performance in marine applications. Common transmission pairings include stern drive options like Alpha One and Bravo One, as well as inboard configurations such as Velvet Drive and ZF. This comprehensive manual provides detailed information essential for the maintenance and repair of your Mercury Mercruiser 350 CID engine. It covers a wide range of topics including general maintenance procedures, troubleshooting common issues, and in-depth engine and transmission service. Specific guidance on fluid recommendations, such as SAE 25W-40 marine engine oil and appropriate coolant types, along with recommended intervals for oil changes, gear lube replacement, and component inspections, are detailed within. This resource is designed to assist owners, mechanics, and technicians in ensuring the optimal performance and longevity of their vessel's propulsion system.