1956–1970 Johnson Evinrude 1.5 HP to 40 HP Outboard Motor Factory Service Manual (P/N ISBN 0-89330-007-1 / 978-0-89330-007-4)

• Covers 1956-1970 Johnson and Evinrude 1- and 2-cylinder, two-cycle outboards from 1.5 to 40 hp, backed by a year-by-year Johnson/Evinrude model cross-reference; not every horsepower applies to every model year.
• The 423-page PDF covers tune-up and troubleshooting, powerhead disassembly and rebuild, fuel and flywheel-magneto ignition service, charging and starting circuits, controls, hand starters, maintenance, and post-overhaul break-in.
• Lower-unit repair is divided into 1.5-4 hp no-shift, 5-25 hp manual-shift, 28-40 hp manual-shift, and 40 hp Electromatic electric-shift designs, with removal, water-pump service, internal inspection, reassembly, adjustment, and installation.
• Fuel-system coverage separates Type I, II, and III carburetors, heat/electric, all-electric, and water chokes, fuel-pump and line tests, pressure-tank service, late-model tank service, and fuel/ignition synchronization.
• Electrical fault isolation extends from the magneto and wiring harness to the generator, regulator, gauges, choke and starter circuits, solenoid, drive gear, and Delco-Remy, Autolite, and Prestolite starter motors.
• Reference material combines model-specific exploded views and wiring drawings with component torque tables, powerhead clearances and wear data, tune-up specifications, gear-oil capacities, and starter, generator, regulator, condenser, and starter-rope specifications.

Model and Publication Scope

This is a Seloc multi-model repair manual, not a single-model OMC factory publication. The procedures are grouped by engine design and horsepower, while the Appendix ties each model year to Johnson codes and Evinrude names or model numbers. The coverage has several narrow runs that matter when identifying an engine: the 15 hp and 30 hp entries are limited to 1956, the 28 hp to 1962-64, and the 35 hp to 1957-59; 1.5 hp coverage begins in 1968 and 4 hp coverage in 1969. The manual is suited to experienced owners and mechanics who can match the engine plate to those tables and are comfortable with precision measurement, electrical testing, pullers, and bearing-installation tools.

What the Repair Procedures Cover

Powerhead work starts with two-cycle operating theory, including cross-flow and loop-scavenged designs, then moves through cylinder-head and reed service, bypass and exhaust covers, upper and lower seals, crankcase separation, connecting rods, pistons, crankshaft inspection, cylinder honing, assembly, installation, and break-in. Crankshaft installation is divided into three groups: 15-40 hp engines; 1.5, 5, 5.5, 6, and 9.5 hp engines; and 3, 4, and 7.5 hp engines.

Lower-unit troubleshooting addresses failure to engage forward or reverse, water intrusion, propeller-hub slip, difficult shifting, jumping out of gear, and a locked gearcase that can imitate a seized powerhead. The Electromatic chapter traces the battery, control box, green and blue shift leads, wiring, and forward/reverse coils before teardown, then distinguishes the babbitt-bearing, knurled forward hub from the needle-bearing, smooth reverse hub during assembly.

Special-tool callouts include OMC coil remover 379784 with kit 379843, seal puller 377565, and bearing remover 309916. Bearing and race service calls out tools 378737, 309033, 309932, and 379247; forward-coil installation uses 379230.

Hand-starter repair is organized by cylinder-and-pinion, coil-spring/swing-arm, and flywheel-mounted designs, with separate coverage for return-spring, no-return-spring, and single-nylon-pawl versions. The maintenance chapter adds engine-number identification, submerged-engine service, winter storage, battery storage, lower-unit upkeep, and preseason preparation.

Drawings, Wiring, and Specifications

The illustration set covers both operating theory and repair, with a complete two-cycle piston-cycle diagram and exploded views of the 1.5, 9.5, 10, and 15-40 hp powerhead groups. Fuel and ignition views show Type I and II carburetors, the pressure fuel tank, and the flywheel magneto. Drivetrain and electrical drawings cover no-shift, Weedless, manual-shift, and Electromatic gearcases plus the three starter-motor families.

Appendix wiring-identification drawings cover 33 hp generator systems for 1965-70, the 35 hp system for 1957-59, and 40 hp standard- and electric-shift generator systems in multiple year groups. A separate 20/25 hp drawing is labeled 1971-72; it does not extend the manual's general repair coverage beyond 1970. The compression-check section evaluates cylinder-to-cylinder balance rather than assigning one universal pressure target to every engine.

Repair Cautions and Safety

Two component-specific cautions deserve attention. Installing the tapered crankcase centering pins from the small-hole side can break the crankcase cover or cylinder block. The head-installation section also warns that automotive head-gasket sealer can cause electrolytic attack on the aluminum cylinder block.

Before powerhead disassembly, the manual calls for the battery and fuel lines to be disconnected. Pressure-tank repair also requires residual tank pressure to be released and fuel vapors kept away from smoking, sparks, and open flame.