This comprehensive service and repair manual covers Mercury/Mariner 40HP, 45HP, and 50HP 4-stroke outboard motors manufactured between 1998 and 2001, including both Bigfoot and non-Bigfoot models. It provides detailed, step-by-step instructions for servicing and repairing all aspects of your outboard motor. The manual begins with a section on specifications, outlining key engine parameters such as length, width, weight, transom height, operating range, fuel recommendations, and more. A dedicated maintenance section offers complete maintenance schedules, charts, and recommendations, including procedures for spark plug replacement, fuel line maintenance, engine oil and gear oil changes, lubrication, anode and bonding wire inspection, battery maintenance, and much more. General information sections provide vital details on identifying numbers, tightening torques, service data, cylinder number, propeller recommendations, and warm-up procedures. The electrical section covers the inspection, removal, installation, and troubleshooting of key components such as the monitor tachometer, starter motor, electric starter system, battery charging system, and more. The ignition system section delves into specifications, special tools, checking ignition timing, spark plug firing order, coil resistance, and crank position sensor resistance. For carbureted models, the manual provides extensive information on carburetor adjustments, disassembly, cleaning, inspection, repair, and reassembly. It includes specifications for idle speed, float height, and jet sizes, along with detailed instructions for adjusting and maintaining the carburetor. The EFI system section covers components such as the fuel injection nozzle, fuel injection pump, throttle body, throttle control lever and linkage, high-pressure fuel line, fuel cooler, fuel hoses, fuel rail pressure regulator, idle speed control assembly, intake manifold, throttle position sensor, low-pressure fuel line/fuel pump, and fuel filter. The powerhead section offers detailed instructions for rebuilding and repairing the engine block, including the cylinder head cover, intake manifold assembly, ring gear cover, air intake, power unit, pump components, oil pump, engine lubrication system, thermostat, cylinder, crankshaft, piston, counter balancer mechanism, and cylinder head assembly. Additional sections delve into the mid-section of the engine, covering engine side cover, driveshaft housing, oil pan, swivel bracket, steering bracket, water pressure valve, lower unit gear housing, and related components. The lower unit section delves into the gear case, propeller, lower unit gears, shimming and adjustment, trim tab, drive shaft, oil seal housing, water pump, and other components. Other important chapters in the manual include sections on attachments and control linkage, throttle and shift linkage, tiller handle, manual starter, diagnostic troubleshooting, and comprehensive wiring diagrams. This complete service manual provides the information you need to perform routine maintenance and address any repairs.

The Mercury/Mariner 1998-2001 Service Repair Manual for 40/45/50 4 Stroke Outboard engines is an indispensable resource for owners, mechanics, and enthusiasts seeking comprehensive information on maintaining and repairing these reliable powerhouses of the water. This manual encompasses a detailed breakdown of various components and systems within the 40, 45, and 50 horsepower 4-stroke outboard motors produced by Mercury and Mariner during this period. The manual provides a wealth of knowledge, ranging from basic maintenance procedures, such as oil changes and filter replacements, to intricate troubleshooting guides for engine malfunctions and component repairs. With its clear and concise language, accompanied by numerous illustrations and diagrams, this manual simplifies the complexities of these engines, making it accessible to users of all skill levels. This manual acts as a user-friendly guide through the intricate workings of these Mercury/Mariner outboard engines, offering valuable insights into their design, operation, and repair. It is a one-stop resource for individuals looking to perform routine maintenance, troubleshoot problems, or undertake more involved repairs. The manual covers a wide range of topics, including engine specifications, maintenance schedules, troubleshooting charts, wiring diagrams, and detailed repair procedures for numerous components, such as the fuel system, ignition system, cooling system, and powerhead. This comprehensive resource empowers owners and mechanics to confidently diagnose and resolve issues, ensuring optimal performance and longevity for their Mercury/Mariner outboard engines.