This comprehensive service and repair manual covers the Mercury/Mariner 9.9/15 HP 4-stroke outboard models manufactured between 1998 and 2001. It provides detailed instructions for servicing and repairing these outboard motors, including the 9.9/15 (4-Stroke) (323 cc) and 9.9/15 Bigfoot (4-Stroke) (323 cc) models. The manual guides you through each maintenance procedure, ensuring your engine remains in optimal operating condition. It emphasizes the importance of following the recommended maintenance schedule to compensate for wear and tear throughout the engine's lifespan. Each chapter comprehensively covers the entire engine, offering step-by-step instructions for removing and installing components. The manual features clear illustrations, diagrams, exploded parts views, photographs, service information, and troubleshooting guides for each section, making it easy to understand and follow. The manual includes detailed specifications for your outboard motor, covering dimensions, weight, transom height, recommended operating range, idle speed, engine type, number of cylinders, displacement, spark plug, fuel supply system, exhaust system, cooling system, lubrication system, starting system, recommended fuel, gear oil capacity, maximum tilt angle, transmission, propeller shaft rotation, propeller type, cylinder compression, engine oil pressure, viscosity rating, engine oil amounts, oil filter change, piston specifications, piston rings, thermostat operating temperature, and much more. The maintenance section provides comprehensive maintenance specifications, charts, intervals, and recommendations, along with step-by-step procedures for tasks such as spark plug replacement, fuel line replacement, fuel hose replacement, breather hose replacement, engine oil change, gear oil change, lubrication, anode and bonding wire inspection, battery maintenance, fuel mixture check, engine oil filter replacement, low-pressure fuel filter replacement, high-pressure fuel filter replacement, ignition timing adjustment, idle speed adjustment, tappet clearance adjustment, water pump inspection and replacement, water pump impeller replacement, propeller nut and pin inspection and replacement, balancer chain inspection, bolt and nut tightening specifications, timing belt inspection, lubrication point identification, oil draining procedure, and oil filter change procedure. The general information section provides essential details including identification numbers, tightening torques, service data, specifications, cylinder number, propeller recommendations, gasoline recommendations (87, 91, 92, 93, race gas), warm-up recommendations, and much more. The electrical section covers the removal and installation of electrical parts holders, as well as inspection, removal, installation, and troubleshooting procedures for components such as the monitor tachometer, starter motor, electric starter system, battery charging system, disassembly and reassembly, cleaning, testing, brush replacement, battery charging system testing, manual start battery charging system tests, battery charging coil testing, battery charging system testing, and rectifier/regulator testing. The ignition section provides specifications, special tools, ignition timing checking procedures, spark plug firing order, ignition timing adjustment, charge coil resistance measurement, crank position sensor resistance measurement, ignition coil resistance measurement, ECM engine speed limiter, spark cut-out reduction, ignition spark, ECM low oil pressure speed control, and oil pressure switch testing. The carburetor section contains information on carburetor specifications, special tools, intake carburetor adjustments, idle speed linkage adjustment, choke adjustment, carburetor removal, disassembly, cleaning, inspection, repair, reassembly, float height measurement, installation, electric choke models installation, idle rpm (out of gear), idle rpm (in forward gear), wide open throttle rpm (WOT), main jet size, pilot jet size, float height, and much more. The electronic fuel injection (EFI) system section covers topics such as EFI system specifications, fuel injection nozzle inspection, fuel injection pump testing, fuel pump operation, throttle body inspection, throttle control lever and linkage adjustments, high-pressure fuel line inspection, high-pressure fuel line testing, fuel cooler inspection, fuel hoses inspection, fuel rail pressure regulator testing, idle speed control assembly inspection, intake manifold inspection, throttle position sensor testing, low-pressure fuel line/fuel pump inspection, fuel filter replacement, and fuel pump testing. The powerhead section provides comprehensive information for a full engine block rebuild. It covers topics like cylinder head cover removal and installation, intake manifold assembly inspection, ring gear cover removal and installation, air intake power unit (powerhead) inspection, measuring pump components inspection, oil pump inspection, engine lubrication system inspection, thermostat inspection and replacement, cylinder inspection, crankshaft inspection, piston inspection, counter balancer mechanism inspection, and cylinder head assembly removal, inspection, and installation. The mid-section covers the engine side cover, driveshaft housing, oil pan, swivel bracket, steering bracket and clamp, water pressure valve, lower unit gear housing, and all associated inspection, removal, installation, cleaning, assembly, and reassembly procedures. The lower unit section explores the gear case, propeller, lower unit gears, shimming and adjustment procedures, trim tab, drive shaft, oil seal housing, water pump and related components, shift guide housing, propeller shaft components, gear bearing, propeller shaft gear housing, and more. Additional chapters in the manual may include topics such as attachments and control linkage, throttle and shift linkage, tiller handle, manual starter, diagnostic troubleshooting, and wiring diagrams.

This comprehensive service manual provides a detailed guide for servicing and repairing 1998-2001 Mercury/Mariner 9.9/15 HP 4-stroke outboard motors. Covering both the 9.9/15 HP and 9.9/15 Bigfoot models with their 323 cc engines, this manual is an essential resource for anyone looking to maintain and troubleshoot these popular outboards. The manual offers step-by-step instructions and illustrations for virtually every aspect of the engine, from basic maintenance tasks like oil changes and spark plug replacement to more complex procedures like rebuilding the carburetor or performing engine diagnostics. The manual's detailed approach ensures that even novice mechanics can confidently tackle a wide range of repairs. It begins with a thorough overview of the engine's specifications, including key dimensions, weight, operating range, and fuel recommendations. This section is crucial for understanding the engine's capabilities and limitations. The manual then dives into comprehensive maintenance schedules, charts, and recommendations for all major components, from the powerhead to the lower unit. It also includes dedicated sections for electrical systems, ignition, carburetor, fuel injection systems, and various other components, providing detailed instructions for inspection, disassembly, cleaning, repair, and reassembly. Additionally, the manual features troubleshooting guides for common engine problems, electrical diagrams, and a comprehensive parts catalog.