Yanmar 2GM20C - Direct Sea Water-Cooled Engine and Fresh Water-Cooled Engine; Modification Method; Testing a Modified Engine; Kit for Modification into a Fresh Water-Cooled Engine

To Next Page

To Previous Page

Main Page

Contents3
Engine Model Name5
Engine Model Name Plate and Clutch Model Name Plate5
Item Descriptions on the Model Name Plates and Information to be Forwarded to Us5
Location of Engine Model Name Plate and Clutch Model Name Plate6
Cylinder Number7
Location of Stamped Engine Serial Number7
General8
Specifications9
Principal Construction12
Performance Curves13
Features17
Engine Cross-Sections18
Dimensions25
Piping Diagrams32
Basic Engine37
Cylinder Block Construction38
Cylinder of Model 1GM10(C) Engine38
Cylinder of Model 2GM20(F)(C) Engine39
Cylinder of Model 3GM30(F)(C) Engine39
Cylinder of Model 3HM35(F)(C) Engine40
Cylinder Block Inspection40
Inspecting each Part for Cracks40
Inspecting the Water Jacket of the Cylinder for Corrosion40
Cylinder Bore Measurement41
Oil and Water Passages41
Color Check Flaw Detection Procedure41
Boring the Cylinder43
Measurement of Distortion on the Upper Surface of the Cylinder44
Purpose of Cup Plug45
How to Drive in the Cup Plug45
Cylinder Head Construction46
Cylinder Head of Model 1GM10(C) Engine46
Cylinder Head of Model 2GM20(F)(C) Engine47
Cylinder Head of Models 3GM30(F)(C) and 3HM35(F)(C)48
Cylinder Head Inspection and Measurement49
Measurement of Carbon Build-Up at Combustion Surface and Intake and Exhaust Ports49
Deposit Build-Up in Water Passages49
Inspection of Corrosion in Water Passages and Anti-Corrosion Zinc49
Measuring Valve Sinkage50
Dismounting and Remounting the Cylinder Head51
Rocker Arm Support Positioning Pin51
Cylinder Head Assembly Sequence51
Tightening the Cylinder Head Bolts and Nuts52
Cylinder Head Nut Loosening Sequence53
Intake and Exhaust Valves, Valve Guide and Valve Spring54
Inspecting and Measuring the Intake and Exhaust Valves54
Inspecting and Measuring Valve Guides55
Valve Spring56
Precombustion Chamber and Top Clearance57
Valve Stem Seal57
Spring Retainer and Spring Cotter Pin57
Intake and Exhaust Valve Rocker Arm58
Insulation Packing58
Components of Valve Rocker Arm58
Measuring the Valve Rocker Arm Shaft and Bushing Clearance60
Valve Rocker Arm and Valve Top Retainer Contact and Wear60
Valve Clearance Adjusting Screw60
Classification of the Intake and Exhaust Valve Rocker Arms60
Adjusting Intake and Exhaust Valve Head Clearance61
Decompression Mechanism62
Adjusting Without a Feeler Gauge62
Disassembling and Reassembling Cylinder Head63
Piston Assembly Construction65
Piston Inspection65
Replacing a Piston66
Piston Pin67
Piston Pin Bushing67
Piston Ring Configuration68
Piston Rings Inspection68
Connecting Rod Ass'y Construction71
Connecting Rod Inspection71
Crank Pin Bushing71
Crank Pin and Bushing Clearance (Oil Clearance)72
Tightening the Connecting Rod Bolts73
Connecting Rod Side Clearance73
Crank Pin Bushing Replacement Precautions73
Piston Bushing and Piston Pin74
Replacing the Piston Pin Bushing74
Crankshaft Ass'y and Bearing Construction75
Constructions of Models 2GM20(F)(C), 3GM30(F)(C) and 3HM35(F)(C) Crankshaft Assembly76
Crank Journal and Crank Pin77
Crankshaft Side Gap79
Disassembly of the Crankshaft80
Side Gap Maintenance Standard and Wear Limit80
Main Bearing Construction82
Inspecting the Crank Bearing82
Inspecting the Thrust Metal83
Inspecting the Intermediate Main Bearing83
Replacing the Crank Bearing84
Crankshaft Oil Seal85
Oil Seal Insertion Precautions85
Oil Seal Type and Size85
Flywheel and Housing86
Specifications of Flywheel86
Dimensions of Flywheel and Flywheel Housing87
Ring Gear89
Position of Top Dead Center89
Construction of the Camshaft90
Camshaft of Engine Model 1Gm10(C)90
Camshaft of Engine Model 2GM20(F)(C)91
Camshaft of Engine Models 3GM30(F)(C) and 3HM35(F)(C)91
Valve Timing Diagram92
Camshaft Inspection92
Camshaft Height92
Journals of Camshaft92
Camshaft Ball Bearing93
Tappets93
Camshaft Deflection93
Push Rods94
Fuel Cam Check94
Fuel Cam Assembly Precautions94
Timing Gear Train Construction96
Timing Gear of Model 1GM10(C)96
Timing Gear of Models 2GM20(F)(C), 3GM30(F)(C) and 3HM35(F)(C)97
Disassembly and Reassembly of the Timing Gear98
Backlash Inspection99
Inspecting the Gear Tooth Surface100
Inspecting the Gear Boss100
Fuel System101
Fuel Injection System102
Fuel Injection System Construction103
Fuel Injection System Specifications103
Injection Pump Construction104
Specifications and Performance of Fuel Injection Pump109
Injection Volume Characteristics of Fuel Injection Pump109
Operation of Fuel Injection Pump111
Fuel Control112
Action of the Delivery Valve and the Sucking-Back of Fuel112
Disassembly of Fuel Injection Pump113
Dismantling of Fuel Pump of Model 2GM20(F)(C), 3GM30(F)(C) and 3HM35(F)(C)114
Inspecting Injection Pump Parts115
Plunger116
Delivery Valve116
Assembling the Fuel Injection Pump117
Plunger Spring and Delivery Valve Spring117
Plunger Guide117
Inspection after Reassembly121
Control Rack Resistance Test121
Fuel Injection Timing121
Injection Pump Adjustment123
Setting Pump on Tester123
Measuring the Sliding Resistance of the Fuel Control Rack123
Adjusting the Plunger Top Clearance123
Checking the Cylinder Injection Interval124
Delivery Valve Oil-Tight Test124
Plunger Pressure Test124
Measuring the Fuel Injection Volume124
Adjustment of Injection Volume for each Cylinder125
Injection Nozzle Construction126
Specifications for Nozzle Valve126
Yanmar Throttle Nozzle127
Nozzle Operation127
Injection Nozzle Disassembly and Reassembly127
Injection Nozzle Inspection and Adjustment128
Carbon and Corrosion on the Nozzle Body128
Checking Nozzle Action128
Adjusting the Nozzle Injection Pressure129
Nozzle Seat Oil Tightness Check129
Checking the Spray Condition129
Inspecting the Nozzle Spring129
Fuel Filter Construction130
Fuel Filter Specifications130
Fuel Filter Inspection130
Fuel Feed Pump Construction131
Fuel Feed Pump Specifications131
Fuel Feed Pump Disassembly and Reassembly132
Inspecting and Adjusting the Fuel Feed Pump132
Checking the Pump for Fuel Oil Leaks132
Checking the Pump for Engine Oil Leaks132
Aging, Breakdown and Cracking of the Diaphragm133
The Contact Area and Mounting Condition of Valve133
Diaphragm Spring and Rocker Arm Spring133
Fuel Tank (Option)134
Fuel Tank Dimension135
Governor136
Governor Construction137
Governor Operation141
Governor Performance141
Governor Disassembly142
Governor Parts Inspection and Replacement142
Regulator Spring142
Sleeve143
Thrust Collar143
Thrust Needle Bearing143
Governor Weight143
Regulator Lever and Handle144
Injection Limiter Construction145
Injection Limiter Inspection145
Injection Limiter Adjustment145
No-Load Maximum Speed Limiter Construction147
No-Load Maximum Speed Limiter Handling Precautions147
Idling Adjuster148
Engine Stop Lever Construction149
Engine Stop Lever Inspection149
Intake and Exhaust System150
Intake and Exhaust System of Model 1GM10(C)151
Intake and Exhaust System of Model 2GM20(F)(C)151
Intake and Exhaust System of Models 3GM30(F)(C) and 3HM35(F)(C)152
Intake Silencer Construction153
Inspection of the Intake Silencer153
Washing the Intake Silencer Element153
Exhaust System154
Exhaust Manifold and Mixing Elbow154
U Type Mixing Elbow154
Exhaust Manifold Inspection155
Mixing Elbow Inspection155
Construction of Breather156
Breather for Model 1GM10(C)156
Breather for Models 2GM20(F)(C) and 3GM30(F)(C)156
Breather for Model 3HM35(F)(C)157
Lubrication System158
Lubricating Oil Passage of Model 1GM10(C)159
Lubrication Oil Passage of Model 2GM20(F)(C)160
Lubrication Oil Passage of Model 3GM30(F)(C) and 3HM35(F)(C)161
Table of Capacity for Lubricating Oil System162
Oil Pump Construction163
Lubricating Oil Pump on Model 1Gm10(C)163
Lubricating Oil Pump on Models 2GM20(F)(C), 3GM30(F)(C) and 3HM35(F)(C)164
Specifications of Lubrication Oil Pump164
Oil Pump Disassembly165
Oil Pump Inspection166
Outer Rotor and Pump Body Clearance166
Outer Rotor and Inner Rotor Clearance166
Pump Body and Inner Rotor, Outer Rotor Side Clearance166
Oil Filter Construction167
Oil Filter Replacement168
Replacing the Oil Filter169
In Case of Oil Leakage169
Oil Pressure Regulator Valve Construction170
Oil Pressure Regulator Valve Specifications171
Oil Pressure Measurement172
Direct Sea-Water Cooling System173
Cooling System Composition174
Cooling Water Route174
Piping174
Cooling Water Passage of Engine Model 1GM10(C)175
Cooling Water Passage of Engine Model 2GM20(C)176
Cooling Water Passage of Engine Models 3GM30(C) and 3HM35(C)177
Water Pump Construction and Operation178
Cooling Water Pump of Engine Model 1GM10(C)178
Cooling Water Pump of Engine Models 2GM20(C) and 3GM30(C)179
Cooling Water Pump of Engine Model 3HM35(C)180
Water Pump Disassembly181
Water Pump Specifications181
Water Pump Reassembly Precautions182
Water Pump Handling Precautions182
Water Pump Inspection182
Thermostat Construction and Operation184
Thermostat Inspection185
Care Must be Taken When Assembling the Thermostat186
Anticorrosion Zinc Principles187
Anticorrosion Zinc Inspection188
Kingston Cock Construction189
Kingston Cock Handling Precautions189
Kingston Cock Inspection189
Bilge Strainer190
Bilge Pump Specifications190
Bilge Pump Performance190
Fresh Water Cooling System191
Cooling System Diagrams192
Cooling System Configuration193
Sea Water Pump194
Fresh Water Pump Construction195
Pump Capacity and Characteristic196
Pump Disassembly196
Pump Inspection and Measurement196
Heat Exchanger Construction198
Water Flow in Water Cooling Tube200
Heat Exchanger Specifications200
Heat Exchanger Disassembly201
Heat Exchanger Inspection and Cleaning201
Cooling Pipe201
Heat Exchanger Body201
Filler Cap Construction202
Filler Cap Pressure Control202
Filler Cap Inspection202
Subtank Function202
Installation of Subtank203
Maintenance During Use203
Thermostat Operation204
Thermostat Construction205
Cooling Water Temperature Switch207
Precautions208
Ventilator208
Cooling Water208
Antifreeze208
Rust Inhibitor209
Idling the Engine When Stopping209
Cleaning the Heat Exchanger Tube209
Modifying the Cooling System210
Direct Sea Water-Cooled Engine and Fresh Water-Cooled Engine211
Modification Method211
Testing a Modified Engine211
Kit for Modification into a Fresh Water-Cooled Engine211
Disassembly of Sea Water-Cooled Engine212
Drain the Cooling Sea Water212
Remove the Cooling Water Pipe212
Remove the Fuel Oil Pipe212
Remove the Fuel Filter213
Remove the Remote Control Bracket213
Remove the Mixing Elbow213
Remove the Exhaust Manifold213
Remove the Thermostat Cover214
Remove the Thermostat Bracket214
Remove the Cooling Water By-Pass Connection214
Remove the CSW Pump214
Remove the Intake Silencer215
Remove the Fuel High Pressure Pipe215
Remove the Lifting Hook at the Front of the Engine215
Remove the Lifting Hook at the Rear or the Engine Together with the Rear Cylinder Head Cover215
Assembling Modified Parts to the Fresh Water-Cooled Engine217
Assemble the Rear Cylinder Head Cover Together with the Rear Lifting Hook217
Assemble the Front Lifting Hook217
Assemble the Fuel Injection Tube217
Assemble the CFW Joint to the Cylinder Block218
Assemble the CFW Pump Assembly218
Assemble the CFW Hose218
Assemble the CSW Pump218
Assemble the Heat Exchanger219
Assemble the Fuel Filter219
Assemble the Fuel Oil Pipe219
Assemble the Mixing Elbow220
Connect the CSW Hose between the Head Exchanger and Mixing Elbow and Tighten the Hose Clamp220
Assemble the CFW Pump V-Belt Pulley220
Assemble the Alternator220
Assemble the Remote Control Bracket221
Cautions When the Engine Is Installed Inboard222
Reduction and Reversing Gear223
Construction224
Power Transmission System226
Arrangement of Shafts and Gears226
Reduction Ratio226
Power Transmission Routine - Forward227
Power Transmission Routine - Reverse227
Drawing228
Construction of Shifting Device230
Action of the Shifting Device231
Changing from Neutral to Forward231
Engagement from Forward to Neutral232
Clutch Shifting Force233
Adjustment233
Inspect for the Following Points236
Inspection and Servicing237
Clutch Case237
Bearing237
Gear237
Oil Seal of Output Shaft239
Input Shaft239
Output Shaft239
Intermediate Shaft239
Notch Slot of Shift Lever Shaft240
Notch240
Notch Spring240
Spring Joint241
Damper Disc241
Disassembly242
Dismantling the Clutch242
Removal of the Output Shaft244
Removal of the Intermediate Shaft245
Dismantling the Side Cover Assembly (Shifting Device)246
Reassembly of Output Shaft247
Reassembly of the Clutch248
Reassembly of the Shifting Device250
Reduction and Reversing Gear Installation256
Remote Control Unit256
Reduction and Reversing Gear Operation and Maintenance257
Lube Oil257
Side Cover257
Friction Plate259
Pressure Plate259
Driving Plate260
Retainer260
Plate Spring260
Shift Ring261
Shift Fork and Shift Lever261
Reassembling the Input Shaft270
Reassembling the Intermediate Shaft270
Installing the Input Shaft and Output Shaft270
Reassembling and Installing the Operating System271
Installing the Output Shaft Coupling272
Marine Gear Models KM2P, KM3P and KM3V273
Forward and Reverse Clutch Operation280
Engagement and Disengagement of Clutch280
Adjustment of Shifting Device281
Measurement and Adjustment of Clearance282
Adjustment of the Remote Control Head283
Marine Gearbox Control Side283
V-Drive Gear, Model KM3V300
KM3V Sectional View301
Shim Adjustment for V-Drive Gear Shaft, and Backlash Adjustment for V-Drive Gear Shaft and Drive Gear315
Backlash Adjustment for V-Drive Near Shaft and Drive Gear316
Dismantling the V-Drive Assembly317
Drain the Cooling Water from the Lube Oil Cooler317
Remote Control System323
Clutch and Speed Regulator Remote Control326
One-Handle Remote Control Composition326
Engine Side Installation327
Movement of Lever for Model 1GM10(C)327
Setting the Reduction and Reversing Gear Side328
Movement of Lever for Models 2GM20(F)(C), 3GM30(F)(C) and 3HM35(F)(C)328
Engine Stop Remote Control330
Electrical System331
Electrical System Diagram of Electric Parts332
Wiring Diagram333
Battery Construction335
Battery Capacity and Battery Cables335
Battery Inspection335
Checking the Electrolyte336
Voltage Test336
Washing the Battery336
Battery Charging337
Battery Storage Precautions337
Battery Charging Precautions337
Starter Motor Specifications and Performance338
Starter Motor Construction338
Starter Motor Operation340
Starter Motor Adjustment and Performance Test340
L-Size Measurement (Gap between Pinion and Pinion Stopper)340
Pinion Movement340
Starter Motor Disassembly341
Plunger Movement341
Pinion Lock Torque Measurement341
Mesh Clearance341
Starter Motor Rear Cover342
Starter Motor Brush Holder342
Starter Motor Yoke342
Starter Motor Armature342
Starter Motor Inspection343
Armature343
Field Coil344
Brush344
Starter Motor Reassembly Precautions346
Starter Motor no Load Test347
Starter Motor Maintenance Standard347
Various Problems and Their Remedies348
Alternator Features349
Alternator Specifications349
Alternator Characteristics349
Alternator Construction350
Alternator Functioning351
Alternator Handling Precautions351
Alternator Disassembling the Alternator352
Alternator Inspection and Adjustment353
Alternator Reassembling the Alternator355
Alternator Performance Test356
Alternator Troubleshooting357
Charging Failure357
Overcharging358
Charge Lamp Failure358
Alternator, Option, 12V/35A359
Alternator, Option, 12V/35A Wiring361
Alternator, Option, 12V/35A Circuit Diagram361
Alternator, Option, 12V/35A Principle of IC Regulator Function361
Alternator, Option, 12V/35A Inspection and Adjustment363
Alternator, Option, 12V/35A Diodes363
Alternator, Option, 12V/35A Rotor363
Alternator, Option, 12V/35A Stator Coil364
Alternator, Option, 12V/35A Brush364
Alternator, Option, 12V/35A Reassembly Precautions365
Alternator, Option, 12V/35A Checking IC Regulator Unit365
Alternator, Option, 12V/35A Performance Test366
Alternator, Option, 12V/35A Standards of Adjustment366
Alternator, Option, 12V/35A Troubleshooting and Repair367
B-Type Instrument Panel368
A-Type Instrument Panel368
Key Switch369
Push Button Switch369
Warning Devices370
Oil Pressure Alarm370
Cooling Water Temperature Alarm370
Alarm Buzzer371
Buzzer for B-Type Instrument Board371
Buzzer for A-Type Instrument Panel372
Construction of Tachometer374
Specifications and Dimensions of Tachometer374
Measurement of Sensor Unit Characteristics375
Operating Instructions377
Fuel Oil and Lubricating Oil378
Properties of Fuel378
Recommended Fuels378
Fuel Selection Precautions378
Properties and Compositions of Fuel of Various National Standards379
Simple Methods of Identifying Fuel Properties380
Troubles Caused by Bad Fuel380
Relationship between Fuel Properties and Engine Performance380
Fuel Handling Precautions381
Action of the Lubricating Oil381
Required Lubricating Oil Conditions381
Classification by Viscosity381
SAE Service Classification and API Service Classification382
Recommended Lubricating Oils383
Engine Oil Replacement and Handling383
Adding Oil383
Oil Capacity384
Engine Operating Instructions385
Preparations before Starting385
Adding Lubricating Oil385
Bleeding the Fuel System385
Starting and Warm-Up386
Checking for Abnormal Sounds by Cranking386
Checking the Electrical System386
Checking Appearance and Exterior386
Starting with One-Handle Remote Control387
After Starting387
Operation388
Stopping388
Checks During Operation388
Operating Precautions388
Storage When Moored for an Extended Period389
Emergency Stop389
Troubleshooting and Repair390
Troubles and Corrective Action at Starting390
Troubles and Corrective Action During Operation391
Disassembly and Reassembly (Direct Sea-Water Cooling Engine)393
Disassembly and Reassembly Precautions394
Disassembly and Reassembly Tools395
Supplementary Packing Agent406
Paint406
Yanmar Cleaner406
Neji Lock Super406
Disassembly General Precautions407
Dismantling Engine Model 1GM10(C)407
Open the Cooling Water Drain Cock and Drain the Cooling Water407
Drain the Lubricating Oil407
Remove the Air Intake Silencer408
Disconnect the Fuel Piping408
Remove the Starter Motor408
Remove the Alternator408
Remove the Rocker Arm Chamber409
Remove the Rocker Arms409
Remove the Cylinder Head409
Remove the Crankshaft Pulley409
Remove the Timing Gear Case410
Remove the Clutch Assembly410
Remove the Flywheel410
Remove the Flywheel Housing410
Remove the Feed Pump411
Remove the Governor Weight Assembly411
Remove the Camshaft Gear411
Remove the Crankshaft Gear and the Lubricating Oil Pump411
Turn the Engine Onto Its Side412
Remove the Oil Pan and the Oil Intake Pipe412
Remove the Piston Connecting Rod Assembly412
Remove the Main Bearing Housing412
Dismantling Engine Models 2GM20(C) and 3GM30(C)413
Remove the Camshaft413
Remove the Tappets413
Disconnect the Remote Control Cables414
Disconnect the Electrical Wiring414
Disconnect the Cooling Water Inlet Pipe and Bilge Pipe414
Remove the Oil Filter415
Install the Flywheel431
Install the Clutch Assembly431
Install the Lubricating Oil Pump431
Assemble the Camshaft Gear and Fuel Cam431
Assemble the Crankshaft Gears432
Install the Governor Sleeve432
Install the Timing Gear Case432
Install the Crankshaft V-Pulley433
Install the Water Pump433
Install the Fuel Injection Pump433
Install the Cylinder Head433
Install the Rocker Arms434
Install the Rocker Arm Cover434
Install the Exhaust Manifold and the Mixing Elbow435
Install the Fuel Pipe435
Install the Starter Motor435
Install the Intake Silencer435
Connect the Electrical Wiring436
Install the Remote Control Cables436
Disassembly and Reassembly (Fresh Water Cooling Engine)437
Disassembly of Fresh Water-Cooled Engine438
Draining the Cooling Water438
Reassembly of Fresh Water-Cooled Engine448
Main Bolt and Nut Tightening Torque458
Packing Supplement and Adhesive Application Points461

Yanmar 2GM20C - Direct Sea Water-Cooled Engine and Fresh Water-Cooled Engine; Modification Method; Testing a Modified Engine; Kit for Modification into a Fresh Water-Cooled Engine

Table of Contents

Related product manuals