1971–1989 Evinrude/Johnson 1.25 HP–60 HP Outboard Motor Service Manual (P/N 1302)

• Covers the 1971-1989 Johnson/Evinrude outboard range shown on the manual cover, from 1 1/4 HP through 60 HP, for 1- and 2-cylinder 2-stroke models. Systems are broken out by horsepower, model year, and hardware design.
• 632-page PDF of the Seloc Johnson/Evinrude Outboards 1971-89 Repair Manual, publication No. 1302.
• Organized into 11 service chapters plus an appendix covering tune-up, powerhead, fuel, ignition, electrical, remote controls, lower unit, hand starters, trim/tilt, maintenance, specifications, and wiring.
• Tracks major OMC design changes including cross-fuel-flow and loop-scavenged powerheads, conventional and low-tension flywheel magneto systems, Type I and Type II CD ignition, VRO/AccuMix oil injection, and distinct shift and gearcase layouts.

Internal Engine and Fuel Systems

This documentation details the mechanical layout of 2-stroke OMC powerheads. Chapters explain the intake, compression, power, and exhaust cycle, then distinguish the cross-fuel-flow deflector-piston design from the loop-scavenging layout used on 40 HP models from 1983 and on the 50, 55, and 60 HP powerheads. Powerhead repair coverage includes head and reed-box service, bypass and exhaust covers, top and bottom seals, connecting rods and pistons, crankshaft inspection, cylinder-block honing, piston/rod installation, crankcase assembly, and break-in. Crankshaft procedures account for different combinations of needle and Babbitt main bearings.

The manual gives measurable inspection limits where they matter. Reed-tip clearance must not exceed 0.010 in. (0.254 mm). It also warns against turning a used reed over to correct sealing; reversing its flex direction can make the reed break in a short time. Piston service covers ring locating pins, groove condition, oversize pistons, cylinder wear, and honing, while the appendix separates piston ring gap and piston-to-cylinder clearance by horsepower and model year.

Fuel sections cover fuel-pump and fuel-line tests, rough idle, excessive consumption, surge, tank service, electric and manual primer chokes, and OMC Type I through Type IV carburetors. Type IV coverage distinguishes fixed- and adjustable-orifice versions used on later 40, 50, 55, and 60 HP engines. Oil-injection coverage includes VRO and AccuMix/AutoBlend. The VRO test data specifies 5-15 psi near full throttle and a 7 in. Hg vacuum limit at idle; AccuMix is described as metering a 100:1 fuel/oil ratio regardless of engine rpm.

Ignition, Electrical, Controls, and Lower Unit

Ignition coverage is divided by system generation: flywheel magneto, low-tension flywheel magneto, Type I capacitor-discharge ignition with timer base, and Type II CD ignition with sensor coil. Type I CD applies to 50 HP 1971-75 and 55 HP 1976-77 engines, while Type II CD appears across many later 2.5-60 HP applications. Repair procedures include polarity checks, breaker-point and condenser testing, stator/charge-coil replacement, timer-base and sensor service, power-pack replacement, timing checks, and fuel/ignition synchronization.

Electrical chapters cover batteries, gauges and horns, generator and alternator charging circuits, choke circuits, starter testing, armature checks, and Bosch and Prestolite starter-motor service. One manual-specific warning matters when diagnosing older magneto systems: feeding 12-volt accessory power into the magneto circuit can damage or destroy the ignition coil, and an automotive-style key switch is not a substitute for the correct magneto switch.

Remote-control service covers double-lever manual boxes, electric shift, Evinrude push-button controls, Johnson single-lever units, and later single-lever remote controls. Lower-unit repair is separated into no-shift, manual-shift, propeller-exhaust mechanical-shift, two-solenoid electric-shift, hydraulic-assist, and later shift-disconnect configurations. Important breakouts include the 50 HP 1971-72 electric-shift unit and the 50 HP 1973-74 hydraulic-assist shift disconnect under the lower carburetor. Procedures cover gearcase removal and disassembly, water-pump service, frozen propeller-shaft work, bearing and seal installation, driveshaft/pinion shimming, reassembly, and functional checks.

Applicable power trim/tilt coverage distinguishes Prestolite and Calco units and includes filling, troubleshooting, hydraulic/mechanical service, and electric-motor testing. Specified fluids are OMC Power Trim/Tilt Fluid or GM Dexron II ATF, and the trim/tilt section gives a 24-26 ft-lb (32.5-35.2 N·m) tilt-tube-nut specification.

Special tools are identified by number, including OMC 378103 for flywheel removal, 315767 for driveshaft/pinion shimming, 316612 for pinion-nut service, and 319875/319876/319877 for bearing-carrier bearing and seal work. The gearcase sections warn that incomplete gear engagement or uneven tightening of the gearcase-head screws can pull the head out of alignment and snap off its mounting ears.

Specifications and Maintenance Data

The appendix contains model-specific torque, tune-up, powerhead, oil/fuel, gear-oil-capacity, starter-motor, regulator, generator, condenser, and starter-rope specifications. Examples include a 0.020 in. breaker-point setting, 0.030 in. spark-plug gap for 1971-81 engines and all 2/4 HP models, and 0.040 in. for 4.5-60 HP engines from 1982 onward. Some lower-unit pinion-nut procedures specify 40-45 ft-lb. Compression diagnosis emphasizes cylinder-to-cylinder balance; a difference greater than 5 psi points to a possible piston, ring, or cylinder problem. Boat-testing guidance uses the specified full-throttle rpm range to evaluate propeller pitch and load.

Maintenance coverage includes engine identification and the post-1979 OMC "INTRODUCES" model-year coding system, submerged-engine service, winter storage, lower-unit maintenance, battery storage, and preseason preparation. Representative illustrations include the 9.9/15 HP 1974-and-on crankshaft assembly exploded drawing, the Type IV fixed-orifice carburetor view, a typical generator exploded drawing, the 50 HP 1973 lower-unit exploded view, the 40/50 HP remote electric-start wire identification drawing for 1986 and on, and the 1989 Johnson/Evinrude 20-30 HP remote-start wiring diagram.

Working on these outboards involves ignition, fuel, hydraulic trim/tilt, and rotating machinery. Follow the manual's isolation, ventilation, water-circulation, and load precautions during testing; it specifically warns that five seconds without cooling-water circulation can damage the water pump and that high-speed no-load operation can cause engine runaway.