1956-1970 Johnson Evinrude 1.5 HP to 40 HP Outboard Motor Factory Service Manual (P/N 58014-8)

• Covers 1956–1970 Johnson and Evinrude outboard motors from 1.5 HP to 40 HP, detailing no-shift, manual-shift, and electric-shift configurations.
• Official OEM publication featuring 423 pages of factory-standard specifications for maintaining timing, fuel delivery, and powerhead performance.
• Contains 47 detailed exploded-view diagrams of powerheads and internal lower unit components.

Operational and Tuning Overview

The 1956–1970 Johnson Evinrude outboard manual documents complete powerhead overhaul, tuning, and maintenance procedures for the specified horsepower range. It breaks down two-cycle combustion theory in depth. Mechanics will find detailed explanations of intake and exhaust cycles, loop scavenging, and cross-fuel flow principles. The documentation also covers cooling system checks, fuel pump diagnostics, and electrical system troubleshooting, including battery service and starter motor repair. Technicians reviewing lower unit service will find exhaustive reference material on manual and electric shift maintenance, as well as hand-starter rebuilds.

Engine Specification Highlights

Engine identification and tuning parameters are laid out across specialized tables in the appendix. Cylinder head bolt torque values are documented in a multi-stage sequence. Spark plug installation is specified at 17 ft-lbs, while compression pressure for engine calibration requires 175 psi. The breaker points need a 0.020" gap for optimal spark timing. Proper crankcase journal lubrication relies on needle bearing grease, and carburetor adjustments should be verified every 100 hours of operation. Because working on marine fuel and ignition systems carries inherent fire and shock risks, always depressurize fuel lines and disconnect the battery before attempting any of the procedures outlined in this reference material.