2003 Yamaha 60C / 70C / 90C Outboard Motor Service Manual (P/N LIT-18616-02-66)

Yamaha's service manual for the 2003 60C, 70C, and 90C outboards covers the 60FETO/60TR, 70BETO/70TR, and 90AETO/90TR model pairs. This is the first edition, October 2003, publication LIT-18616-02-66, with cover reference 6H2-28197-1F-11.

Text search, navigation, and wiring detail: Service text and diagram legends are searchable, with bookmarks for chapters and major sections. Some labels within wiring drawings require visual lookup and zooming. The "Return to Index" bookmark requires a separate index file that is not included.

• Power unit repair: Powerhead removal and installation, cylinder and piston inspection, crankshaft checks, reed-valve inspection, and thermostat testing.

• Fuel and oil injection: Carburetor overhaul and link synchronization, electrothermal valve checks, oil-pump delivery tests, and oil-level warning diagnosis.

• Lower unit service: Water-pump repair, clutch-dog and shift-mechanism inspection, gear shimming, backlash measurement, and gearcase leakage testing.

• Bracket and power trim/tilt: Bracket service, trim-sensor adjustment, hydraulic pressure tests, air bleeding, and trim-motor inspection.

• Electrical diagnosis: CDI peak-voltage testing, ignition and charging checks, starter-motor overhaul, and model-specific wiring diagrams.

• Trouble analysis: Symptom charts covering starting faults, rough idle, overheating, hard shifting, weak tilt holding, and poor battery charging.

Written primarily for Yamaha dealers and their trained mechanics, this manual assumes a basic understanding of mechanical and electrical service procedures.

Power Unit Repair and Inspection

Internal engine repair covers crankcase separation, piston and ring service, crankshaft alignment checks, and reassembly. Inspection tables distinguish the 60/70 hp and 90 hp groups for piston clearances, connecting-rod measurements, and crankshaft deflection.

Cylinder-head warpage limits and tightening sequences accompany the power-unit exploded views. Yamaha also warns that spinning a crankshaft bearing with compressed air can damage the bearing.

Carburetors and Oil Injection

Fuel-system routing views identify the fuel and oil connections. Carburetor inspection covers float-height settings, needle valves, jets, the enriching fuel pump, and the electrothermal valve.

Link adjustment differs between the 60/70 hp and 90 hp groups. Oil-pump delivery testing, pump-link adjustment, bleeding, and warning-system checks are documented separately.

The carburetor cleaning cautions explain how steel wire can enlarge jet openings and affect engine performance.

Lower Unit Shimming and Repair

Shim-selection procedures distinguish USA/Canada service tools from those used in other markets. Pinion, forward-gear, and reverse-gear calculations use the gearcase's stamped F/R/P corrections, with different reverse-gear data for the 60/70 hp and 90 hp groups.

Backlash checks relate paired forward/reverse readings to pinion height, helping identify a gearcase setup error before reshimming. Lower-unit exploded views show the shift slide, clutch dog, shafts, bearings, and water-pump assembly.

Bracket and Power Trim/Tilt Service

Separate hydraulic layouts and repair sections cover short-transom 6H308 and long-transom 6H1-15 / 62F-02 power trim-and-tilt units. Pressure-test data, cylinder service, motor brush and armature checks, and air bleeding are matched to these configurations.

The factory-adjusted gear pump is replaced as an assembly. The separate pressurized hydraulic tilt cylinder is covered for inspection only and must not be overhauled.

Electrical Baselines and Maintenance Specifications

Electrical testing covers charge-coil resistance and peak voltages for the CDI unit, pulser coils, and crank-position sensor. The manual identifies the peak-voltage adapter YU-39991 / 90890-03169 and explains conditions that can affect readings.

Remote-control box and digital-meter diagrams supplement the engine wiring drawings. Starter repair covers clutch, brush-holder, and armature inspection; separate checks address relays, the rectifier/regulator, oil-level sensors, and neutral switches.

Periodic service includes full-retard/full-advance ignition timing, timing-plate and pickup adjustment, and battery CCA, MCA, and reserve-capacity requirements. Maintenance schedules, dimensional views, and component torque tables provide additional reference data.

Safety notes address flammable gasoline, workshop ventilation, and support of the tilted outboard during bracket work.

English PDF and Included Pages

One printable English-language 196-page PDF: 189 pages of service chapters and section indexes, five introductory/index pages, one front cover, and one rear cover. All are included in the total; there is no separate supplement.