This manual covers the Mercury MerCruiser Bravo & Alpha 4.3L MPI sterndrive models, specifically MCM 4.3L MPI Alpha & Bravo sterndrives with serial numbers 0M300000 and above. These V6 petrol MPI engines, displacing 4.3 liters (262 CID), are engineered for reliable marine performance. This service repair manual provides comprehensive guidance for maintaining and servicing these powerful sterndrive units. The purpose of this manual is to offer detailed repair and service information for both DIY enthusiasts and experienced mechanics. It includes step-by-step instructions with detailed illustrations and diagrams covering general information, maintenance, troubleshooting, removal and installation procedures, engine mechanical aspects, electrical systems, fuel systems, cooling systems, exhaust systems, and power steering. This resource is designed to help owners and technicians efficiently perform repairs and keep their Mercury MerCruiser sterndrives operating at peak performance.