Part of the Yanmar Operator Manuals.
Publication 0AAYV-G00203 is Yanmar's own operation manual for the 12AYM-WGT, 12AYM-WET and 12AYM-WST marine propulsion engines, delivered here as the complete 70 page factory book in PDF, not a rewrite of it.
Inside are the procedures Yanmar wrote for running-in a fresh installation, checking before starting, running under load, stopping, and laying the engine up for long-term storage. The Periodic Maintenance section works through the fuel system, lubricating oil system, cooling water circuits, turbocharger, rubber hoses, control cables and electrical parts, while the troubleshooting charts walk starting failure, speed drop, oil pressure faults, overheating and sudden shutdown back to their causes.
A guessed valve lash or belt tension figure is how a healthy engine gets hurt. This manual prints the real numbers, 0.3 mm intake and 0.5 mm exhaust clearance among them, so everything goes back together on Yanmar's settings and the engine runs.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Lntroduction | 2 | |
| For Your Safety | 4-11 | Safety Symbols, Safety Precautions, Warning Labels, Precautions for Lifting the Engine, Engine Nameplate |
| Specifications | 12-24 | Location of Components, Functions of Major Components, Piping Diagram of Major Engine Parts, Control System |
| Fuel Oil, Lubricating Oil and Coolant | 25-27 | Fuel, Lubricating Oil, Coolant |
| Running-In | 28-39 | Initial Operation, Cranking, Checking Before Starting |
| Operation | 40-47 | Starting, Engine Warm-Up, Notice While Running with Load, Stopping, Long-Term Storage |
| Periodic Maintenance | 48-61 | Periodic Maintenance Schedule, Fuel System, Lubricating Oil System, Cooling Water System, Turbocharger, Rubber Hoses, Control Handle and Cables, Electrical Parts |
| Troubleshooting and Countermeasures | 62-65 | Starting Failure, Rotational Speed Drops Spontaneously, Lubricating Oil Pressure Out of the Specified Pressure, Coolant Temperature Is Too High, Engine Stops Suddenly |
| Wiring Diagrams | 66-70 | Color Coding, Starter Switch, Instrument Panel, Battery, Alternator, Sensors |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Fuel filter element replacement | Every 500 hours | p. 50 |
| Fuel-water separator element replacement | Every 500 hours | p. 50 |
| Seawater pump impeller replacement | Every year | p. 56 |
| Alternator drive belt tension (deflection) | 3.9 mm at 5-6 N load | p. 60 |
| Fuel injection pump lubricating oil capacity (each pump) | 1.5 l | p. 30 |
| Hydraulic governor lubricating oil capacity | Approximately 0.8 l | p. 30 |
| Air tank pressure | 2.45 MPa - 2.94 MPa | p. 39 |
| Alternator drive belt deflection | 3.9 mm at 5-6 N load | p. 60 |
| Valve clearance Intake | 0.3 mm | p. 61 |
| Valve clearance Exhaust | 0.5 mm | p. 61 |
| Fuel oil viscosity at 50 °C | 3-8 mm²/s | p. 25 |
