1996–2010 Yamaha 50G, 60F, 70B, 75C, 80A, 90A 2-Stroke Outboard Service Manual (P/N 62F28197Z6C1)

Yamaha’s OEM service manual covers the 50G, 60F, 70B, 75C, 80A and 90A 2-stroke outboard families and their model-specific configurations. Publication P/N 62F-28197-Z6-C1, first edition December 1996, provides maintenance, diagnosis and repair procedures with separate specifications for the covered engine groups.

• Fuel and carburetion: Fuel-pump inspection, carburetor disassembly and assembly, Prime Start and choke configurations, float-height checks, and carburetor linkage synchronization.

• Power unit repair: Powerhead removal, cylinder and piston inspection, crankshaft checks, reed-valve service, thermostat testing, and model-specific engine assembly procedures.

• Lower unit service: Gearcase disassembly, clutch-dog and shaft inspection, water-pump replacement, shim selection, backlash measurement, and leakage testing.

• Bracket and trim systems: Steering-pivot and mount service, trim-sensor adjustment, power trim and tilt overhaul, hydraulic pressure testing, and air bleeding.

• Electrical diagnosis: C.D.I. testing, charge and pulser coil checks, crank-position sensor inspection, starter-motor overhaul, and oil-level warning-system tests.

• Workshop reference: Exploded assembly views, torque tables, electrical resistance specifications, maintenance schedules, wiring diagrams, and symptom-based trouble-analysis charts.

Written primarily for Yamaha dealers and trained mechanics, this manual assumes a basic understanding of the mechanical and electrical principles involved in outboard service.

Fuel, Lubrication and Routine Maintenance

The periodic inspection schedules cover initial break-in service through annual checks. Carburetor linkage instructions distinguish the 50–70HP arrangement from the 75–90HP arrangement, while carburetor stamp marks identify the applicable jetting and pilot-screw settings.

Oil-injection coverage includes pump-output testing, linkage adjustment, oil-line bleeding and warning-system operation. Premix configurations such as C60ER/60FE, C60TR/60FET and C80TR/80AET receive their own carburetor and electrical references.

The carburetor section flags a specific repair trap: cleaning jets with steel wire can enlarge their openings and affect engine performance.

Powerhead Inspection and Internal Repair

The power-unit chapter extends beyond removal and installation. It covers cylinder taper and out-of-round checks, piston clearance, piston-ring inspection, connecting-rod play, crankshaft alignment and bearing condition.

Separate assembly instructions address the crank assemblies used in the two engine groups, including connecting-rod big-end bearing assembly on the 75–90HP engines. Reed valves, thermostat, oil-pump drive gears, cylinder head and exhaust covers are also covered.

Factory tolerances let a technician compare measured wear with the relevant inspection limits before deciding whether components need replacement or machining.

Gearcase, Water Pump and Trim Hydraulics

Lower-unit repair includes forward, reverse and pinion gear inspection, propeller-shaft housing service, water-pump installation and pressure-based leakage checks. Shim-selection methods distinguish U.S./Canadian tooling from the procedures for other markets.

The bracket chapter separates short-transom power trim and tilt units marked 6H308 from long-transom units marked 6H1-15 and 62F-02. Hydraulic circuit illustrations accompany cylinder, valve and motor service, fluid filling, bleeding and pressure tests.

The factory-adjusted P.T.T. gear pump is treated as a replacement assembly rather than an internally serviceable component. The separate hydraulic tilt cylinder is inspected and replaced as an assembly; Yamaha warns against overhauling it because it is highly pressurized.

Support the raised outboard securely and observe the manual’s fuel-handling and hydraulic precautions during service.

Ignition Tests and Wiring References

The electrical section includes the 1-Y ignition-tester procedure using C.D.I. tester YU-91022-B, plus component resistance and continuity checks. These tests help distinguish C.D.I., coil, sensor and wiring faults before components are replaced.

Visual references include engine-group wiring diagrams, electrical lead-routing views, remote-control-box and digital-meter diagrams, hydraulic circuit illustrations, and crankshaft measurement sketches. The trouble-analysis charts connect symptoms such as hard starting, overheating, poor charging and hard shifting with components and chapter references.

A Sample of Engine Inspection and Adjustment Data

These examples show a small selection of the manual’s inspection and adjustment specifications.

Cylinder-head warpage is limited to 0.1 mm (0.004 in). For 50, 60 and 70HP engines, crank width “A” is specified at 57.90–57.95 mm (2.280–2.281 in).

For the 90HP engine, full-advance ignition timing is 22 ± 1° BTDC at the specified test speed of 5,000 ± 500 rpm. The 75–90HP oil-pump test specifies 3.10 ± 0.70 cm³ per outlet over three minutes, with the engine at 1,500 rpm, the pump lever fully advanced and oil at 10–30°C.

The periodic-service section also specifies a spark-plug tightening torque of 25 Nm (18 ft-lb).

Bookmarked PDF and Diagram Viewing

Navigation and small labels: Embedded PDF bookmarks provide access to chapters and many individual service topics. Text search is unavailable for the service pages. Small wiring color codes and connector labels on the checked diagrams are readable when enlarged; zooming and rotating the page make dense areas easier to follow.

One printable PDF download contains 408 pages: 406 manual pages plus a separate front cover and final contact page, both already included in that total. The factory content is presented in English, French, German and Spanish.