Part of the Yanmar Repair Manuals.
Yanmar's service manual for the D27A and D36A diesel outboards takes both engines from complete teardown to final backlash adjustment, and it earns its keep the moment you have one on a stand with the powerhead open. Chapter 2 sequences the disassembly and reassembly, Chapter 3 walks every engine part (cylinder block, piston and connecting rod, crankshaft, cylinder head, unit injector, governor) through inspection with the measurements to make, and Chapter 4 handles the drive unit from swivel bracket to lower gear case and cooling water pump.
Guessing a torque figure on a flywheel nut or an injector set bolt is how a rebuild fails on the water. Chapter 8 lists the real numbers, and Chapter 7 gives the service standard tables for wear limits.
The 142 pages arrive as one bookmarked PDF (publication A0A5055-JC03), so the section you need, whether that is the wiring diagram, a backlash procedure, or the periodical inspection table, is seconds away.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 4-16 | Specifications, Exterior View, Cross-Sectional View |
| Disassembly and Reassembly | 17-59 | Preparations Before Disassembly and Reassembly, Tools, Measuring Instruments and Service Equipment, Exploded View of Parts, Reassembly Procedures |
| Inspection and Service Procedures for Engine Parts | 60-89 | Service Procedures for Engine Parts, Cylinder Block, Piston and Connecting Rod, Crankshaft, Camshaft, Cylinder Head, Valve Arm Case, Intake/Exhaust Valve Arm and Unit Injector |
| Reassembling and Servicing of Drive Unit | 90-110 | Swivel/Steering Bracket, Clamp Bracket, Upper Case, Bottom Cowling and Fitting Parts, Lower Gear Case, Cooling Water Pump and Cooling Water Piping, Steering Handle |
| Piping Diagram | 111-113 | Fuel System Components, Lube Oil System Components, Cooling Water System Components, Thermostat Valve Opening Temperature |
| Electric Equipment | 114-124 | Generator, Starting Motor, Warning Device, Wiring Diagram |
| Service Standard | 125-131 | Service Standard Table |
| Main Bolt Tightening Torque | 132-134 | Engine Bolt Tightening Torque, Drive Unit Bolt Tightening Torque, General Bolt and Nut Tightening Torque |
| Backlash Adjustment | 135-137 | Pinion Gear Backlash Adjustment, Forward Gear Backlash Adjustment, Reverse Gear Backlash Adjustment, Propeller Shaft Backlash Adjustment |
| Periodical Inspection | 138-139 | Periodical Inspection Table |
| Option | 140-142 | Diesel Outboard Propeller Guard Holes |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Injector tap set bolt tightening torque | 2.6~2.8 kgf-m | p. 133 |
| CW pump case tightening bolt torque | 0.7~0.9 kgf-m | p. 133 |
| Overheat alarm buzzer activation | O (activates) | p. 118 |
| Cylinder head temperature OFF | 115°C | p. 119 |
| Crankshaft Side Gap (Standard) | 0.15-0.45 mm | p. 125 |
| Flywheel Tightening Nut Torque | 16.5~17.5 kgf-m | p. 133 |
| Pinion Gear Tightening Nut Torque | 9.0~10.0 kgf-m | p. 133 |
| Backlash between Pinion and Forward Gear (Standard) | 0.1~0.25 mm | p. 129 |
