This comprehensive service and repair manual for 1999-2002 Mercury 30HP and 40HP 4-stroke EFI outboard motors provides detailed instructions and information to help you maintain and repair your engine. It covers models 30/40 MH, 30/40 ELPT, and 40 ELPT BIGFOOT. The manual outlines service procedures for the entire outboard, emphasizing the importance of adhering to the maintenance schedule to ensure optimal engine performance. The manual features detailed step-by-step instructions for all procedures, accompanied by clear illustrations, diagrams, exploded parts views, and photographs for enhanced understanding. Each chapter begins with an overview of the relevant system or component, including specifications, troubleshooting tips, and service information. This manual covers a wide range of topics, including: * **Specifications:** Detailed specifications for your specific outboard model, encompassing aspects such as engine type, dimensions, weight, fuel system, cooling system, lubrication system, and more. * **Maintenance:** Comprehensive maintenance schedules, charts, and recommendations. This section guides you through procedures for essential maintenance tasks such as spark plug replacement, fuel line inspection, engine oil changes, gear oil changes, water pump maintenance, and more. * **General Information:** Essential general information regarding your outboard, including identification numbers, tightening torque values, service data, cylinder number, and gasoline recommendations for optimal performance. * **Electrical System:** Detailed information on components like the starter motor, battery charging system, and electrical parts, with instructions for inspection, removal, installation, and troubleshooting. * **Ignition System:** In-depth coverage of the ignition system, addressing aspects such as ignition timing, spark plug firing order, ignition coil resistance, and ECM-related components. * **Carburetor:** Comprehensive information for carbureted models, including procedures for carburetor adjustment, rebuild, removal, inspection, and cleaning. * **EFI System:** A dedicated section focusing on the electronic fuel injection system, covering components like the fuel injection pump, fuel injectors, throttle body, fuel lines, and fuel filter. * **Powerhead:** Detailed instructions for disassembly, inspection, and reassembly of the powerhead, including components such as the cylinder head, crankshaft, pistons, and oil pump. * **Mid-Section:** Detailed information on the mid-section, encompassing components like the engine side cover, driveshaft housing, oil pan, swivel bracket, steering bracket, and water pressure valve. * **Lower Unit:** Comprehensive information on the lower unit, including the gear case, propeller, drive shaft, water pump, and related components. * **Attachments & Control Linkage:** Detailed instructions for adjusting and maintaining various attachments and control linkage components. * **Throttle & Shift Linkage:** Detailed instructions for inspecting and adjusting the throttle and shift linkage system. * **Tiller Handle:** Instructions for inspecting and adjusting the tiller handle. * **Manual Starter:** Information on the manual starter system. * **Diagnostic Troubleshooting:** A troubleshooting guide to assist in diagnosing common engine problems. * **Wiring Diagrams:** Detailed wiring diagrams to aid in understanding the electrical system. This comprehensive service manual provides all the necessary information to keep your Mercury outboard running smoothly.

The Mercury 30/40 HP EFI 4-Stroke outboard motors, produced from 1999 to 2002, are a reliable and popular choice for small to mid-sized boats. These models are known for their smooth operation and fuel efficiency, thanks to their advanced electronic fuel injection system (EFI). The EFI system ensures precise fuel delivery, optimizing performance and reducing emissions. The 4-stroke design offers quiet operation and reduced vibration compared to older 2-stroke engines. This service manual provides comprehensive repair and maintenance information for these models, covering everything from basic maintenance tasks to complex engine rebuilds. This manual is an essential resource for anyone who wants to keep their Mercury 30/40 HP EFI 4-Stroke outboard running smoothly. It contains detailed instructions and diagrams for every aspect of the engine, from the powerhead to the lower unit. The manual also includes troubleshooting guides, specifications, and wiring diagrams to help you diagnose and resolve any issues that may arise. With its clear and concise language, detailed illustrations, and thorough coverage of all major components, this service manual is the perfect tool for both experienced mechanics and DIY enthusiasts. This manual unlocks the secrets to maintaining and repairing your Mercury outboard, ensuring that you can enjoy countless hours of trouble-free boating experiences.