Johnson Evinrude 1,25 hp, 12 hp, 15 hp, 18 hp, 20 hp, 25 hp, 30 hp, 35 hp, 40 hp, 50 hp, 55 hp, 60 hp Outboard Engine Factory Manual 1971–1986 (P/N 18-01302)

This 631-page PDF is a Seloc repair manual for Johnson and Evinrude 1- and 2-cylinder two-stroke outboards from 1.25 through 60 HP. Its principal model coverage spans 1971-1989, while a separate appendix sheet adds tune-up specifications for selected 1989 and 1990 models. Coverage is model-specific rather than blanket: procedures are divided by horsepower, year range, ignition design, starting arrangement, and lower-unit type. The depth is suited to marine mechanics and experienced DIY owners who can identify the exact engine configuration, use electrical test equipment and pullers or presses, and work from component-specific specifications.

• Powerhead repair starts with two-cycle theory, cross-fuel-flow and loop-scavenging operation, and reed-valve function, then proceeds through cylinder-head, crankcase, piston and connecting-rod, crankshaft, bearing, seal, and cylinder-block work. Disassembly, inspection, honing, reassembly, break-in, torque, and wear-reference information are included.
• Fuel-system coverage distinguishes Type I through Type IV carburetors, with removal, disassembly, cleaning, inspection, assembly, installation, and adjustment procedures. Separate material handles fuel pumps and tanks, manual and electric primer chokes, plus VRO and AccuMix/AutoBlend oil-injection troubleshooting and service.
• Ignition diagnosis separates conventional flywheel magneto, low-tension flywheel magneto, Type I CD with timer base, and Type II CD with sensor coil. The chapter covers harness and key-switch checks, condensers and breaker points, stator and charge/sensor coils, power packs, timing, and fuel/ignition synchronization.
• Electrical repair includes marine batteries and dual-battery arrangements, gauges and warning circuits, generator and alternator systems, choke circuits, starter and solenoid testing, starter-drive service, and Bosch and Prestolite starter-motor disassembly, armature testing, reassembly, and installation.
• Lower-unit procedures are divided among no-shift, shift-without-disconnect, manual-shift, propeller-exhaust mechanical-shift, two-solenoid electric-shift, and mechanical-shift/hydraulic-assist units. Applicable sections cover removal, water-pump service, internal teardown, bearing, seal, clutch-dog and gear inspection, reassembly, lubrication, installation, and functional checks.
• Controls, starting, and trim cover Johnson single-lever boxes, Evinrude pushbutton controls, double-lever and remote-control boxes, cable-end fittings, seven hand-starter types, emergency starting, and power trim/tilt troubleshooting and electric-motor service.
• Specifications and service tools include torque tables, tune-up and powerhead data, lubrication and gear-oil information, starter, generator, regulator, condenser, and starter-rope specifications. The text identifies OMC tools by number, including Seal Remover 387780, Coil Locating Ring 317001, terminal removers 322697-322699, and model-specific lower-unit bearing and shimming tools.

Model and Configuration Breaks

The lower-unit chapter separates the 50 HP 1971-1972 two-solenoid electric-shift design, the 1973-1974 hydraulic-assist arrangement, and later mechanical-shift units. Ignition applications are likewise mapped by horsepower and model year instead of treated as interchangeable. The lubrication appendix distinguishes early premix engines, later small-engine recommendations, 40-60 HP non-VRO models, and oil-injected configurations; it does not apply one mixture rule to the entire range.

Maintenance material covers engine serial-number identification, corrosion protection, propeller selection, submerged-engine service, winter storage, lower-unit maintenance, battery storage, and preseason preparation. Safety and boating sections also address fuel handling, flotation, emergency equipment, navigation, and accident-reporting requirements.

Exploded Views and Wiring Reference

A dedicated sequence contains 11 exploded powerhead, crankshaft, and cylinder-block drawings. The appendix provides 25 wire-identification and wiring-diagram pages, A-22 through A-46. Representative illustrations include the 9.9/15 HP crankshaft and cylinder-block views, the 20 HP crankshaft assembly, the 40 HP powerhead, low- and high-output alternator schematics, the 1982-1985 20-60 HP remote-electric-start diagram, and 1989 20-30 HP tiller- and remote-start diagrams.

Repair Cautions

The manual flags incorrect water-pump impeller orientation and installation as causes of premature failure or cut vanes. It also warns that automotive head-gasket sealer can promote electrolytic attack on aluminum powerhead castings. Fuel vapor, high-voltage ignition, wound starter springs, rotating components, and raised trim/tilt assemblies require proper ventilation, electrical isolation, secure support, and close attention to the safety notes before repair work begins.