2002 Mercury 240 EFI Jet Drive Factory Service Manual (P/N 90-884822)

This Mercury Marine service manual, 90-884822, is the December 2001 edition for the 240 EFI Jet Drive, starting with model year 2002. Coverage begins at powerhead serial 0E384500 and pump unit serial 0E379931.

The file is a 431-page PDF with searchable text. Some wiring labels are embedded in graphics and cannot be found with text search.

• Powerhead repair: Powerhead removal and installation, internal disassembly, cylinder inspection, and piston, connecting rod, crankshaft, and reed block service.

• Fuel and oil injection: Fuel pump diagnosis, VST service, injector and fuel rail testing, oil pump priming, and air-purging procedures.

• Ignition and starting: Ignition coil ohm tests, sensor diagnostics, alternator testing, and solenoid-driven Bendix starter disassembly, inspection, and rebuilding.

• SmartCraft and warnings: Analog and digital instrument wiring, System Monitor V2.0 calibration, Engine Guardian fault information, and gauge tests.

• Jet pump: Stator servicing, wear ring replacement, impeller clearance inspection, pinion gear shimming, and gear backlash measurement.

• Installation and cooling: Hull cutout dimensions, exhaust layout, reverse gate and cable adjustment, cooling pressure diagnosis, and automatic bilge siphon setup.

Written for Mercury dealers' mechanics and company service personnel, this manual assumes familiarity with Mercury products and training in the recommended service procedures and tools.

Ignition, Starting, and ECM Diagnosis

DDT diagnosis covers ECM inputs, fault history, cylinder misfire testing, and output load tests. The listed setup pairs Digital Diagnostic Terminal 91-823686A2 with adapter harness 84-822560A5; detailed terminal operating procedures are referenced to a separate DDT manual.

Electrical test tables cover ignition-coil connector pins, the crank position sensor, and the manifold absolute pressure (MAP) sensor. The throttle position sensor (TPS) and idle speed are not adjustable; ignition timing is ECM-controlled.

The Starter Circuit Troubleshooting Flow Chart supports starting-system fault isolation. Starter repair extends to armature, brush, and clutch inspection. Its cleaning notes warn that solvents can damage insulation and wash lubricant out of the drive clutch and planetary gears.

EFI Fuel Delivery and Oil Injection

The low- and high-pressure EFI fuel-route charts and Fuel Rail Electrical/Fuel Determination chart help distinguish fuel-supply problems from injector-circuit, ignition, or compression faults before major fuel-system disassembly.

Vapor Separator Tank (VST) coverage includes float checks, pressure regulator testing, and high-pressure pump removal. Fuel-pressure specifications and gauge 91-881834A1 are listed with the test procedures. VST disassembly notes warn that twisting the pump during removal can damage its wiring harness.

Oil-system procedures distinguish DDT Reset Break-In from Oil Pump Prime and cover the remote tank, engine reservoir, and low-oil warning circuit. The emissions section explains factory-setting requirements and certification-label identification.

SmartCraft Instruments and Wiring

System Monitor V2.0 and System Tach & Speed coverage extends to fuel-tank calibration, depth-sensor options, alarm messages, and Engine Guardian power reduction. Available display functions depend on the engine and installed sensors.

Color remote-control and dash wiring diagrams cover SmartCraft and non-SmartCraft configurations. The color engine-wiring sheet is labeled Model Year 2001-1/2.

Powerhead Repair, Cooling, and Storage

The two-stroke V-6 powerhead chapter covers cast-iron cylinder honing, standard and oversize pistons, half-keystone piston rings, and crankshaft bearing inspection. Component-specific torque tables, lubrication data, spark plug specifications, and wear limits support reassembly.

The Water Flow diagram traces cooling through the cylinder block, expansion chamber, and adapter plate. Pressure diagnosis and temperature-sensor tests accompany water-bypass and flushing coverage.

Maintenance routines for off-season storage, such as fuel stabilization and engine flushing, are defined alongside protocols for handling complete water submersion.

Jet Pump Repair and Installation

The pump chapter extends into pinion and impeller shaft bearings and seals. Shimming and backlash procedures identify which component replacements require the gearset to be checked and reset. Special tools include Jet Pump Tool Kit 91-809957A1.

Installation instructions cover tunnel grommets, ride plate sealing, steering and shift cables, reverse gate stops, and exhaust-outlet position relative to the loaded waterline.

Follow the manual's safety procedures for pressurized fuel, electrical isolation, and suspended powerheads.

File Format and Readability

The page count includes one cover, three introductory pages, 407 pages in Sections 1–5, and 20 pages in Section 6, Color Diagrams. Four Notes pages are included within Sections 1–5.

The color section contains six large-format diagrams, six title pages, six legend pages, a contents page, and one otherwise blank navigation page. These pages are already included in the total.

Embedded bookmarks cover the main sections and detailed service topics. Small wire codes, connector labels, and pin numbers on the larger wiring sheets require zooming for comfortable reading.