Yanmar 2QM15 Marine Diesel Engine Service & Repair Manual (P/N 2F015A)

• Covers 1970s–1980s Yanmar 2QM15 and 2QM15G marine diesel engines, including 2-cylinder vertical water-cooled and pre-combustion variants
• Original 221-page OEM PDF publication (Yanmar form 2F015A) featuring 47 exploded-view schematics for the base engine, fuel, lubrication, and cooling systems
• Essential reference material for accurate marine engine repair
• Details essential assemblies including the reduction reversing gear, wet clutch, remote control system, centrifugal governor, alternator, starter motor, and bilge pump
• Features specific visual aids such as electrical wiring diagrams, performance curves, sectional views, exterior views, system diagrams, timing gear train drawings, and power transmission schematics

Engine Construction and Systems

Having direct access to factory specifications prevents costly trial-and-error parts replacement and minimizes dockside downtime by allowing you to accurately measure components before ordering spares. This manual provides a comprehensive look at the engine's architecture, offering the technical descriptions needed for thorough overhauls, routine maintenance, and precise troubleshooting. It details the cylinder block, cylinder head, and internal rotating assemblies like the crankshaft and pistons. You get clear operational data for the Bosch-type injection pump, fuel filter, and feed pump. Working on marine diesel systems carries inherent risks, so referencing factory-approved tolerances is crucial to maintain safe operating pressures and prevent catastrophic failure. The documentation also covers the complete cooling system configuration, including rubber-impeller pumps and specialized thermal management. Furthermore, it empowers you to handle complex procedures in-house instead of paying for an expensive marine diesel workshop, covering advanced tasks like extracting wet-type cylinder liners, lapping valve seats, calibrating fuel injection timing, and adjusting nozzle injection pressures with shims.

Technical Reference and Specifications

Having the right numbers on hand speeds up any repair. This guide outlines the critical wear limits and build parameters for the 2F015A-series. Final stage cylinder head bolt torque is strictly rated at 15–16 kg-m (108.5–115.7 ft-lbs). The valve specification table dictates an intake and exhaust clearance of 0.20 mm. For the cooling system, the thermostat operates within a defined window of 42–52°C. You will also find the precise lubrication pressure requirement of 2.5–3.5 kg/cm² (35.56–49.78 lb/in.²) at 3,000 rpm. Exhaustive tolerance charts for valve guides, pistons, and ring grooves streamline your inspection process, ensuring your work meets original factory standards.