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 Seloc repair manual, P/N 18-01302, covers Johnson and Evinrude 1- and 2-cylinder two-stroke outboards from 1.25 through 60 HP. Its principal model coverage spans 1971–1989, with an appendix sheet providing tune-up specifications for selected 1989 and 1990 models. Procedures are divided by horsepower, year range, ignition design, starting arrangement, and lower-unit type.

PDF Search, Bookmarks, and Wiring Detail

Text search and diagram detail: Manual text is not searchable in this PDF. Three embedded bookmarks jump to broad file sections rather than individual chapters. Small wiring labels on the checked diagrams are readable when enlarged; some fine linework is faint.

One printable PDF contains 631 pages, including seven contents pages and a 46-page appendix. The appendix includes one tune-up specification sheet for selected 1989 and 1990 models.

Powerhead, Ignition, and Gearcase Repair

The following highlights are selected manual contents. Other topics include boat loading and anchor selection.

• Powerhead repair: Step-by-step disassembly, inspection, honing, and reassembly for cylinder heads, crankcases, pistons, connecting rods, crankshafts, bearings, and seals, plus break-in guidance.

• Fuel systems: Type I through Type IV carburetor overhaul and adjustment, fuel-pump and tank service, manual and electric primer chokes, and VRO and AccuMix/AutoBlend service.

• Ignition diagnosis: Flywheel and low-tension magneto troubleshooting, Type I and Type II CD testing, timing checks, and fuel/ignition synchronization.

• Electrical repair: Battery, gauge, and warning-circuit checks; generator and alternator testing; starter and solenoid diagnosis; and Bosch and Prestolite starter-motor overhaul.

• Lower units: Gearcase removal, water-pump service, bearing and seal replacement, clutch-dog and gear inspection, reassembly, lubrication, and functional checks for the applicable designs.

• Controls, starting, and trim: Remote-control box repair and cable fittings, seven hand-starter designs, emergency starting, and power trim/tilt troubleshooting and electric-motor service.

• Specifications and tools: Torque, tune-up, and powerhead data; lubrication and gear-oil references; starter, generator, regulator, condenser, and starter-rope specifications; and identified OMC service tools.

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 Inspection and Assembly

Two-cycle theory explains cross-fuel-flow and loop-scavenging operation, along with reed-valve function. Crankshaft assembly instructions distinguish needle main bearings from configurations using Babbitt center and bottom bearings.

The powerhead chapter also covers bypass and exhaust covers, top and bottom seals, and model-specific wear references. Its repair sections begin after the preliminary access work has been completed, rather than detailing every external component removal for every engine.

Carburetor and Oil-Injection Differences

Type IV coverage distinguishes fixed- and adjustable-orifice carburetors. VRO and AccuMix/AutoBlend have separate operating descriptions, troubleshooting, and service material.

The lubrication appendix distinguishes earlier premix engines, later small-engine recommendations, 40–60 HP non-VRO models, and oil-injected configurations. Recommendations depend on the engine and operating conditions.

Ignition and Electrical Fault Finding

Type I CD ignition uses a timer base, while Type II CD uses a sensor coil. Diagnostic material addresses wiring harnesses and key switches, breaker points and condensers, stators, charge and sensor coils, and power packs.

Starter sections include drive-gear service, armature testing, reassembly, and installation. Battery guidance covers dual-battery arrangements, while choke-circuit checks are treated separately from starter and charging-system tests.

Lower-Unit Configuration Breaks

Separate sections cover no-shift, shift-without-disconnect, manual-shift, propeller-exhaust mechanical-shift, two-solenoid electric-shift, and hydraulic-assist units.

The chapter distinguishes the 50 HP 1971–1972 two-solenoid electric-shift design, the 1973–1974 hydraulic-assist arrangement, and later mechanical-shift units. These divisions help match gearcase teardown and test procedures to the unit being serviced; ignition applications are likewise mapped by horsepower and model year.

The no-shift and shift-without-disconnect sections provide service procedures without dedicated troubleshooting instructions. Other applicable sections include frozen propeller-shaft work, bearing installation, and driveshaft/pinion shimming.

Remote Controls, Hand Starters, and Trim

Control-box procedures distinguish Johnson single-lever units, Evinrude pushbutton controls, double-lever boxes, and later single-lever remote controls. Cable-end fitting instructions accompany the relevant control arrangements.

Power trim/tilt coverage distinguishes Prestolite and Calco systems. The oil pump is replaced as a unit, and the manual directs deeper hydraulic disassembly to a shop equipped and staffed for that work.

Exploded Views, Wiring, and Service Tools

A dedicated sequence contains 11 exploded powerhead, crankshaft, and cylinder-block drawings. Examples include the 9.9/15 HP crankshaft and cylinder-block views, the 20 HP crankshaft assembly, and the 40 HP powerhead.

The appendix provides 25 wire-identification and wiring-diagram pages, A-22 through A-46. References include low- and high-output alternator schematics, the 1982–1985 20–60 HP remote-electric-start diagram, and separate 1989 20–30 HP tiller-electric and remote-start diagrams.

OMC tool references include Seal Remover 387780, Coil Locating Ring 317001, terminal removers 322697–322699, and model-specific lower-unit bearing and shimming tools.

Seasonal Maintenance and Repair Cautions

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

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.

Selected Reed-Clearance and Compression Checks

For the reed-to-base-plate inspection, the manual gives a maximum clearance of 0.010 in. (0.254 mm) at the reed tip with the reed at rest.

Its compression-check discussion emphasizes cylinder-to-cylinder balance: a difference greater than 5 psi can indicate a problem with the lower-reading cylinder, including piston, ring, or cylinder wear.