Yanmar 6SY-STP | 6SY-655 | 8SY-STP Service Workshop Manual

Workshop Service and Repair Manual for the Yanmar 6SY / 8SY marine engines, an absolute gem for any Yanmar owner. This full workshop manual covers every component, service and repair procedure in full Yanmar factory specification with clear step by step technical drawings for the Yanmar straight 6 cylinder and V8 engines with torque setting values throughout each chapter, this is the most comprehensive service manual available as used by boatyards and independent marine engineers the world over.

Below is an exhaustive list of the items covered within this manual:

Engines:

6SY-STP
6SY-655
8SY-STP

Revision History
Safety Precautions
Engine Outline Drawings
Engine Piping Diagrams
Location Of Nameplates
Engine Nameplate (Typical)
Diesel Fuel
Engine Oil
Engine Coolant
Principal Engine Specifications
Engine Service Standards
Tightening Torques For Standard Bolts And Nuts
Introduction
Periodic Maintenance Schedule
Periodic Maintenance Procedures
Epa Requirements
Safety Precautions
Special Torque Chart
Special Service T Cols
Measuring Instruments
Tests And Adjustments
Repair

Engine:
Safety Precautions
Introduction
Principal Engine Specifications
Adjustment Specifications
Cylinder Head Specifications
Camshaft And Timing Gear Train Specifications
Crankshaft And Pistons Specifications
Special Torque Chart
Special Service Tools
Measuring Instruments
Tests And Adjustments
Adjust Valve And Unit Injector Clearances
Repair

Cylinder Head
Cylinder Head Components
General Guidelines
Remove And Install Rocker Covers
Remove The Cylinder Head
Disassemble The Cylinder Head
Clean The Cylinder Head Components
Inspect The Cylinder Head Components
Replace The Valve Stem Seals
Replace The Valve Seat
Machine The Valves
Machine The Valve Seat Inserts
Replace The Valve Guides
Replace The Unit Injector Sleeves
Reassemble The Cylinder Head
Install The Cylinder Head
Pistons And Cylinder Liners
Remove And Disassemble Piston And Connecting Rod
Inspect The Connecting Rods
Replace The Wrist Pin Bushing
Inspect The Pistons And Piston Rings
Assemble The Piston And Connecting Rod
Remove The Cylinder Liners
Measure The Cylinder Liner Height
Install The Cylinder Liners
Install The Piston And Connecting Rod

Flywheel And Flywheel Housing
Flywheel Housing Components – 6Sy Engines
Flywheel Housing Components – 8Sy Engines
Remove The Flywheel
Flywheel Inspection And Repair
Replace The Rear Crankshaft Seal
Remove The Flywheel Housing
Install The Flywheel Housing
Install The Flywheel

Timing Gear Train
6Sy Components
8Sy Components
Check The Camshaft Timing
Remove The Front Gear Housing – 8Sy
Install The Front Gear Housing – 8Sy
Intermediate Gear
Camshaft Gear
Crankshaft Gear
Remove The Camshaft
Replace The Camshaft Bearings – 6Sy
Replace The Camshaft Bearings – 8Sy
Install The Camshaft

Cylinder Block And Crankshaft
Remove The Crankshaft
Measure The Oil Clearance
Inspect The Crankshaft
Recondition The Crankshaft
Inspect The Cylinder Block
Install Crankshaft
Replace The Front Crankshaft Seal
Exhaust Manifold
Replacing Gaskets
Lifting The Engine

Fuel System
Specifications
Special Service Tools
Fuel System Components
Fuel Delivery Components
Fuel Injector Components
Tests And Adjustments
Adjust The Unit Injectors
Measure The Fuel Feed Pump Pressure
Test The Fuel Pressure Relief Valve
Repair
Remove The Unit Injector
Install The Unit Injector
Replace The Fuel Feed Pump
Replace The Fuel Filter And Fuel Filter/ Water Separator
Replace Return Fuel Line
Bleed The Fuel System

Cooling System:
Specifications
Special Service Tools
Tests And Adjustments
Pressure Testing Cooling System And Filler Cap
Testing The Thermostat.
Repair
Drain, Flush And Fill The Engine With Engine Coolant
Venting The Cooling System – 8Sy Engines Only
Coolant Pump Removal
Install Coolant Pump
Remove And Install Pulley
Change The Coolant Pump Seal
Remove And Install Thermostat
Remove And Install Fresh Water Charge Air Cooler
Remove And Install Seawater Charge Air Cooler – 6Sy Engines Only
Seawater Pump
Check Or Replace The Zinc Anodes

Lubrication:
Specifications
Special Service Tools
Tests And Adjustments
Check The Engine Oil Pressure
Repair
Remove And Install The Oil Cooler
Remove And Install Oil Cleaning Components
Replace The Engine Oil Filter – 8Sy
Clean The Centrifugal Engine Oil Cleaner
Oil Pump

Turbocharger
Introduction
General Information
Oil Leaks
Foreign Bodies
Air And Exhaust Leaks
Oil Filter
Cleaning The Compressor Wheel
Specifications
Special Service Tools
Component Location
6Sy Engines
8Sy Engines
Tests And Adjustments
Measuring Charge Pressure
Repair
If The Turbocharger Does Not Operate:
Remove Turbocharger.
Inspect The Turbocharger
Measure The Radial And Axial Clearance
Install The Turbocharger.

Starter Motor
Starter Motor Specifications
Starter Motor Troubleshooting
Remove And Install Starter Motor
Repair Starter Motor – Bosch Je
Components
Brush Replacement
Replace Solenoid

Alternator:
Specifications
Calculating Alternator Capacity
Alternator And Charging System Troubleshooting
Test And Inspection
Output Test
Brush Length
Rotor
Repair
Replace Alternator Belt

Ems:
Introduction
Specifications
Special Service Tools
Function Description – Engine Management System (Ems S6)
General
Component Location
Engine Speed Sensors – T28 And T29
Charge Air Pressure And Temperature Sensor – T26
Coolant Temperature Sensor – T27
Oil Pressure Sensor – T25
Ems S6 Control Unit E44
Ems S6 Control Unit Connections
Repair
Replace The Ems S6 Control Unit
Remove The Ems S6 Wiring
Installing Ems S6 Wiring

Troubleshooting:
Introduction
Troubleshooting Chart
Fault Codes
Working Procedure
After Troubleshooting Or Repair