This comprehensive service and repair manual provides detailed instructions for maintaining and repairing Mercury and Mariner outboard motors ranging from 45 to 115 horsepower, covering models manufactured from 1965 to 1989. The manual covers a wide range of topics, ensuring you have the information needed for any repair or maintenance task. Within the manual, you'll find detailed specifications for each covered model, including vital information like overall dimensions, weight, transom height, recommended operating range, idle speed, engine type, cylinder configuration, displacement, spark plug type, fuel system details, cooling system description, lubrication system specifications, starting system information, recommended fuel types, gear oil requirements, and gearcase oil capacity. Additionally, it provides maximum tilt angles, transmission operation details, propeller shaft rotation, and cylinder compression specifications. The maintenance section is a valuable resource, offering complete maintenance schedules with recommended intervals for various tasks. This includes step-by-step procedures for essential maintenance items like spark plug replacement, fuel line inspection and replacement, breather hose replacement, engine oil changes, gear oil changes, anode and bonding wire inspection, battery maintenance, fuel mixture checks, engine oil filter replacement, low and high-pressure fuel filter replacement, ignition timing adjustments, idle speed adjustments, tappet clearance checks, water pump inspection and impeller replacement, propeller nut and pin maintenance, balancer chain inspection, and lubrication point checks. The manual also provides general information sections for each model, covering key identification numbers, tightening torque values, service data, cylinder numbering, propeller recommendations, gasoline (fuel) recommendations, warm-up procedures, and general operating guidelines. The electrical section details the removal and installation of electrical components, along with detailed inspection, removal, installation, and troubleshooting procedures for essential systems like the monitor, tachometer, starter motor, electric starter system, battery charging system, and associated components. Users will find detailed instructions for disassembly, cleaning, testing, brush replacement, and reassembly of these systems, as well as specific tests for the battery charging coil, battery charging system, and rectifier/regulator. The ignition system section provides specifications for ignition components, details on using special tools, instructions for checking ignition timing, identifying spark plug firing order, adjusting ignition timing, testing charge coil resistance, measuring crank position sensor resistance, inspecting ignition coil resistance, troubleshooting the ECM (Engine Control Module) for speed limiting and spark cut-out functions, understanding ECM low oil pressure detection and speed control, and inspecting the oil pressure switch. For models equipped with carburetor systems, the manual provides comprehensive instructions for carburetor adjustments, rebuilds, removal, inspection, cleaning, and setting to factory specifications. Within this section, you will find specifications, specialized tool requirements, intake carburetor adjustments, idle speed linkage adjustments, choke operation details, comprehensive removal and disassembly procedures for cleaning, inspection, and repair, reassembly steps, float height measurement methods, and installation instructions. Additionally, it covers the adjustment of idle rpm (both in-gear and out-of-gear conditions), wide open throttle (WOT) rpm, main jet size, pilot jet size, and float height, providing specific values for different models. For outboard models with electronic fuel injection (EFI) systems, the manual offers detailed information about the EFI system, including specifications for components like fuel injection nozzles, fuel injection pumps, throttle body assembly, throttle control lever and linkage, high-pressure fuel lines, fuel cooler, fuel hoses, fuel rail pressure regulator, idle speed control assembly, intake manifold, throttle position sensor, low-pressure fuel lines, fuel pumps, and fuel filter. The powerhead section (also known as the power unit) is a key part of the manual, containing comprehensive instructions for completely rebuilding the engine block back to factory specifications. It includes information on removing, inspecting, and installing the cylinder head cover, intake manifold assembly, ring gear cover, air intake, power unit (powerhead), measuring pump components, oil pump, engine lubrication system, thermostat, cylinder, crankshaft, piston, counter-balancer mechanism, and cylinder head assembly. The mid-section of the manual covers engine components like the engine side cover, driveshaft housing, oil pan, swivel bracket, steering bracket and clamp, water pressure valve, lower unit gear housing, and provides detailed procedures for inspection, removal, installation, cleaning, assembly, and reassembly. The lower unit section focuses on the gearcase, propeller, lower unit gears (including shimming and adjustment), trim tab, driveshaft, oil seal housing, water pump and related components, shift guide housing, propeller shaft components, gear bearing, and propeller shaft gear housing. The manual also includes additional chapters covering attachments and control linkage, throttle and shift linkage, tiller handle, manual starter, diagnostic troubleshooting, and wiring diagrams. This comprehensive service and repair manual is an invaluable resource for owners and mechanics working on Mercury and Mariner outboard motors covered by its scope. The detailed information, step-by-step procedures, and troubleshooting guides make it an indispensable tool for maintaining and repairing these popular outboards.

This comprehensive service and repair manual for Mercury and Mariner outboard motors is a valuable resource for anyone who wants to maintain or repair their 45 to 115 HP two-stroke engines. Covering a broad range of models manufactured between 1965 and 1989, this manual provides detailed instructions and illustrations for a variety of tasks, from routine maintenance to complex engine overhauls. Whether you're a seasoned mechanic or a DIY enthusiast, this manual offers the information necessary to keep your Mercury or Mariner engine running smoothly. The manual encompasses a vast array of topics, including detailed specifications for each model, step-by-step procedures for maintenance and repairs, troubleshooting guides, and comprehensive wiring diagrams. You'll find information on everything from replacing spark plugs and adjusting carburetors to performing complete engine rebuilds. The manual covers essential components like the powerhead, mid-section, lower unit, ignition system, electrical system, fuel injection system, and the carburetion system. With its clear explanations, detailed illustrations, and easy-to-follow instructions, this manual helps you diagnose problems, perform repairs, and maintain your Mercury or Mariner outboard motor to factory specifications. This manual is a must-have for any owner of a Mercury or Mariner outboard motor during this era.