1996–2000 Mercury Mariner 45 Jet, 50, 55, and 60 HP Outboard Service Manual (P/N 90-817643R1)

• Serial-based model coverage: Mercury Marine factory service manual P/N 90-817643R1 covers 45 Jet, 50, 55, and 60 HP outboards, including 55 Marathon, 55 SeaPro, 60 Marathon, 60 SeaPro, and 60 Big Foot configurations. Coverage starts at U.S. serial 0D000750 and Belgian serial 09671687. The set contains 565 PDF pages across 24 files.
• Powerhead repair depth: Documents powerhead removal, disassembly, cylinder-block and crankcase inspection, honing, piston and ring service, crankshaft and connecting-rod work, reed-block inspection, reassembly, torque sequencing, installation, and test-run checks.
• Fuel and electrical diagnosis: Covers WME carburetors, fuel-pump variants, enrichener testing, fixed- and variable-ratio oil injection, ADI ignition, charging and starting systems, DVA and resistance tests, timing, carburetor synchronization, and throttle-linkage adjustment.
• Trim and tilt systems: Provides separate repair chapters for Power Trim Designs I-IV and Manual Tilt Designs I-IV, with hydraulic flow diagrams, leak-down checks, electrical fault tracing, motor and pump service, valve-block work, seal placement, purging, and bleeding.
• Lower-unit repair: Separates the standard gear housing, the 60 Big Foot/SeaPro/Marathon gear housing, and the 45 Jet drive. Procedures include water-pump service, bearing and seal replacement, gear and shaft setup, pressure testing, reassembly, and installation.
• Installation, steering, and controls: Includes transom mounting, Ride-Guide and dual-steering setups, remote-control and throttle/shift cable adjustment, electrical connections, tiller-handle and Co-Pilot service, the Jet 45 tiller adaptor, and rewind-starter repair.

Technical Documentation Overview

The powerhead material is built around the 51.8 cu. in. (849 cc), three-cylinder, two-cycle loop-charged engine family. Exploded assemblies and factory repair procedures cover the cylinder block and crankcase, induction manifold and reed blocks, crankshaft, pistons, connecting rods, throttle linkage, thermostat, and cooling passages. Inspection data includes bore, piston, ring, crankshaft, reed, and wear-limit specifications, with component-specific torque tables and lubricant and sealant references.

The general-information section also covers propeller selection and installation, trim-fluid checks, lubrication points, cooling-system flushing, compression, and water-pressure testing. Storage, submersion recovery, corrosion care, painting, and decal application are included.

Coverage is organized by hardware configuration and serial breaks rather than by a blanket model-year range. The alternator-driven, distributorless capacitor-discharge ignition is treated as an ADI system, with separate black- and red-stator procedures. U.S. ignition test charts split 55/60 Marathon and SeaPro applications at serial 0G277479/0G277480, and 45 Jet/50/60 electric-start applications at 0G277605/0G277606. The manual directs technicians to verify the stator part number on earlier units before selecting a DVA or resistance chart. Timing tables also separate the 55 HP calibration from the 50/60 HP settings.

Fuel-system coverage is specific to the covered configurations. WME-43, WME-44, and WME-45 carburetor families are identified by model application, with main-jet and bowl-vent data, high-altitude rejetting charts, float and idle-mixture adjustments, troubleshooting charts, and removal, cleaning, inspection, and reassembly procedures. Separate fuel-pump layouts are shown for standard 50/60 models and 55/60 SeaPro/Marathon models. The oil-injection chapter distinguishes fixed- and variable-ratio pumps and covers pump-drive components, carburetor-to-oil-pump synchronization, system filling and bleeding, warning-module diagnosis, reservoir service, and drive-gear installation.

Variant-Specific Repair Coverage

Mid-section material separates 55-model transom-bracket hardware from 50/60 assemblies, then breaks the trim equipment into four power-trim designs and four manual-tilt designs. Each design has its own component views and hydraulic theory, so the correct chapter can be matched before disassembly. Depending on design, procedures cover trim or shock rods, motors, pumps, manifolds, valves, accumulators, memory pistons, seals, relays, leak-down diagnosis, and final bleeding or purging.

The lower-unit chapters prevent a common scope mismatch. Standard 50/55/60 gearcases use a different repair section from the larger 4-1/4-inch torpedo, 2.3:1 gear housing fitted to 60 Big Foot, SeaPro, and Marathon applications. Both chapters cover teardown and setup for the driveshaft, propeller shaft, gears, pinion, shift mechanism, bearings, races, seals, bearing carrier, and water pump. Pinion location or depth, forward-gear backlash, pressure testing, lubricant filling, and shift verification are documented. The 45 Jet section is separate again, covering mounting height, cavitation checks, shift-cable setup, impeller clearance, liner replacement, bearing-carrier service, steering-pull adjustment, and jet-drive installation.

Diagrams, Tools, and Service Notes

Section 2D contains 12 named model and control wiring diagrams, while the charging-system chapter adds four more. Examples include the Model 45 Jet Electric Start diagram, rectifier- and regulator-type 50/60 electric-start diagrams, the 55 Manual Start diagram, manual- and electric-start RED-stator diagrams, and COMMANDER 2000 side-mount remote-control circuits. Hydraulic power-trim flow diagrams, oil-injection flow layouts, troubleshooting flowcharts, exploded assemblies, and gearcase setup views support the mechanical chapters.

Tool references include the Multi-Meter/DVA Tester 91-99750, Direct Voltage Adapter 91-89045, Flywheel Puller 91-73687A1, Lifting Eye 91-90455, Pinion Gear Location Tool 91-817008A2, and Bearing Preload Tool 91-14311A2, along with design-specific pullers, drivers, seal installers, and backlash fixtures.

The manual also flags several repair traps. An ADI switch box can be damaged if it is not grounded during testing. Air left in the oil-injection hoses after service can lead to engine damage. The gearcase chapters warn that excess lubricant on top of the driveshaft can prevent full engagement and damage both the powerhead and gear housing when the retaining fasteners are tightened. High-voltage ignition work, battery isolation, propeller-area service, lifting, and suspended-outboard precautions are addressed throughout the publication.