Model:
3YM30, 3YM20, 2YM15
Model Variant:
3YM30, 3YM20, 2YM15 marine diesel engines
Production Years Covered:
N/A - not specified; manual covers these models across multiple years
Generation:
YM series (3YM30, 3YM20, 2YM15)
Target Audience:
Marine technicians and DIY boat owners servicing Yanmar YM series engines
Application:
Auxiliary propulsion and generator drive in sailboats and small craft
Compact Design:
2- and 3-cylinder configurations for tight engine compartments
Cooling Options:
Direct or indirect cooling depending on configuration
Transmission:
Reduction and reversing gear (e.g., KM3V, KM4V series)
Manual Type:
Service Manual
Delivery:
Instant download
Compatibility & Requirements
Operating System Compatibility:
All versions of Windows & Mac
Software Requirements:
Adobe PDF Reader
Included Sections:
General, Inspection and adjustment, Troubleshooting, Disassembly and reassembly, Inspection and servicing of basic engine parts, Fuel injection equipment, Intake and exhaust system, Lubrication system, Cooling water system, Reduction and reversing gear, Remote control, Electrical system, Service standards, Tightening torque for bolts and nuts, Colophon
Page Count:
N/A - not specified in the source data
General Information:
Engine identification, specifications, and general service procedures
Inspection and Adjustment:
Routine checks and adjustments for engine and subsystems
Troubleshooting:
Diagnostic procedures for common engine and system faults
Disassembly and Reassembly:
Step-by-step engine teardown and rebuild instructions
Basic Engine Parts:
Inspection and servicing of cylinder head, pistons, crankshaft, bearings, etc.
Fuel Injection Equipment:
Service and calibration of fuel injection pump, injectors, and related components
Intake and Exhaust System:
Air intake, exhaust manifold, and associated components
Lubrication System:
Oil pump, filter, galleries, and lubrication circuit
Cooling Water System:
Raw water pump, heat exchanger, thermostat, and cooling circuit
Reduction and Reversing Gear:
Transmission service, including KM3V, KM4V series
Remote Control:
Throttle and shift remote control systems
Electrical System:
Charging, starting, and electrical components
Service Standards:
Specifications for wear limits, clearances, and tolerances
Tightening Torque:
Torque values for bolts and nuts
Adjustment Procedures:
Valve clearance, belt tension, and other routine adjustments
Diagnostic Procedures:
Symptom-based troubleshooting and testing
Overhaul Procedures:
Complete disassembly, inspection, and reassembly of engine and components
Repair Procedures:
Servicing and replacement of worn or damaged parts
Specifications:
Detailed service standards and tolerances
Illustrations:
N/A - not specified in the source data
Parts Information:
Component identification and part numbers where applicable
File Format:
PDF (searchable, bookmarked, zoomable)
Compatibility:
Windows, macOS, Linux, iOS, and Android — any device with a PDF reader
Requirements:
A PDF reader application (e.g. Adobe Acrobat Reader, free)
Searchability:
Fully text searchable for fast lookup of any topic
Print Quality:
High-resolution digital pages, printable at full clarity
Binding Type:
N/A — digital download, no physical binding
Paper Type:
N/A — digital download, no physical paper
Engine Type:
Marine Diesel Engine
Configuration:
3YM30, 3YM20: 3 cylinders; 2YM15: 2 cylinders
Cooling Method:
Direct or indirect cooling (depending on configuration)
3YM30 Displacement:
1.266 L (77.2 cu. in.)
3YM30 Power:
21.3 kW (28.6 hp) @ 3760 RPM
3YM20 Displacement:
1.051 L (64.1 cu. in.)
3YM20 Power:
16.2 kW (21.7 hp) @ 3760 RPM
2YM15 Displacement:
0.776 L (47.3 cu. in.)
2YM15 Power:
11.1 kW (14.9 hp) @ 3760 RPM
Injection Equipment:
Serviced and detailed in manual
Standard Transmission:
Reduction and reversing gear (e.g., KM3V, KM4V series)
Optional Transmission:
N/A - not specified for this model
Gear Ratios:
Variable (refer to specific model/gearbox specifications in manual)
Control:
Remote control system covered in manual
Lubrication:
N/A - refer to transmission section for fluid type and capacity
Wheelbase:
N/A - not applicable to marine engines
Length:
N/A - not specified for this model, refer to installation drawings
Width:
N/A - not specified for this model
Height:
N/A - not specified for this model
Dry Weight:
N/A - not specified; varies by model and configuration
Curb Weight:
N/A - not applicable to marine engines
Oil Change:
Refer to manual for recommended intervals
Fuel Filter:
Recommended periodically as per manual
Impeller:
Refer to cooling water system section
Engine Oil Capacity:
Approximately 2.1 L (varies slightly by model; refer to manual)
Coolant Type:
Ethylene Glycol based coolant recommended (refer to manual)
Transmission Fluid:
N/A - refer to transmission section
Known Issues / Wear Items
Common Wear Items:
Impellers, belts, filters, and anodes
Adjustments:
Alternator belt tension adjustment: refer to inspection and adjustment section
