This service repair manual covers Mercury Mercruiser #3 Marine Engines produced between 1978 and 1984. These robust engines, based on GM engine blocks with Mercury Marine additions and marinization, are available in Inline 4-Cylinder, Inline 6-Cylinder, and V-8 Cylinder configurations. The manual details a wide array of specific engine models, including MCM 120, MCM 140, MCM 165, MCM 470, MCM 485, MCM 898, MCM 228, MCM 260, MCM 330, MCM 400 Cyclone, MCM 440 Cyclone, MCM 460 Cyclone, and various Turbo models, alongside their associated Velvet Drive and Mercury Marine transmissions. It also addresses different cooling systems, fuel systems including various carburetor types, exhaust components, and drive systems. This comprehensive English-language manual provides essential information for the maintenance and repair of your Mercury Mercruiser engine. It includes detailed tear-down and rebuild procedures, maintenance schedules, troubleshooting guides for common issues, torque specifications, and complete wiring schematics. With over 1000 pages of step-by-step instructions, part diagrams, and detailed illustrations, this manual is an indispensable resource for owners, mechanics, and technicians seeking to ensure the optimal performance and longevity of their marine engines. The manual is searchable, bookmarked, and printable, offering convenient access to critical technical data. 🏷️ Basic Information Identification Make: Mercury Mercruiser Model: Mercruiser #3 Marine Engines (GM 4 Cylinder, GM 6 Cylinder, GM V-8 Cylinder) Year: 1978-1984 📋 Manual Details Manual Information Manual Type: Service Repair Manual Language: English Page Count: 1092 Format: PDF Download Features Features: • Complete tear down and rebuild • Pictures and part diagrams • Torque specs • Maintenance procedures • Troubleshooting guides • Detailed illustrations • Diagrams • Wiring schematics • Step-by-step instructions • Printable pages • Bookmarked • Searchable Compatibility Compatible Devices: • Windows • Mac • APP ISO • iPhone • iPod • Android Delivery Method Delivery Type: Instant Download Requirements Software Requirement: Adobe PDF Reader ⚙️ Engine Specifications Engine Types Engine Types Covered: • GM 4 Cylinder • GM 6 Cylinder • GM V-8 Cylinder Engine Identification Specific Engine Models: • MCM 120 • MCM 120R • MCM 140 • MCM 140R • MCM 165 • MCM 470 • MCM 470R • MCM 485 • MCM 488R • MCM 898 • MCM 898R • MCM 228 • MCM 228R • MCM 260 • MCM 260R • MCM 330 • MCM 330 (8-W) • MCM 370/400 • MCM 400 Cyclone • MCM 440 Cyclone • MCM 460 Cyclone • MCM 475 Turbo • MCM 470TR • MCM 230TR • MCM 260TR • MIE 470 • MIE 228 • MIE 230 • MIE 255 • MIE 260 • MIE 330 • MIE 340 Engine Features Engine Description: Based on GM engine blocks with Mercury Marine additions and marinization. Engine Variations Variations Covered: • Seawater Cooled • Closed Cooled • Driveshaft Extension Models • Cyclone Models • Turbo Models Engine Configurations Configurations: • Inline 4-Cylinder • Inline 6-Cylinder • V-8 Cylinder Power Steering Power Steering System: Covered within the manual. Fuel Systems Carburetor Types Covered: • Rochester 2 Barrel • MerCarb 2 Barrel • Rochester 4 Barrel • Holley 4 Barrel Exhaust Systems Exhaust Components: • Manifolds • Elbows • Risers • Collectors Cooling Systems Cooling System Types: • Seawater Cooled • Closed Cooled • Specific models like 470/485/488 Drive Systems Drive System Components: • Driveshaft Models • Propeller Shaft 🔧 Transmission Transmission Types Transmission Types Covered: • Velvet Drive (Borg-Warner) • Mercury Marine Transmission 🔧 Maintenance General Maintenance Maintenance Scope: Comprehensive maintenance procedures for all covered models. Troubleshooting Troubleshooting Coverage: Detailed troubleshooting guides for common issues.