Market Position:
Yanmar YM series engines are designed for marine auxiliary and propulsion use, targeting boat builders, marine technicians, and DIY owners requiring reliable diesel power.
Competitive Advantage:
Known for durability, fuel efficiency, and compact design; widely supported with parts and service documentation.
Key Features:
Direct injection, fresh water cooling (on some models), low noise and vibration, easy maintenance access.
Manual Type:
Service and repair manual
Delivery Method:
Instant download
Page Count:
N/A - not specified for this manual
Coverage Areas:
General, inspection and adjustment, troubleshooting, disassembly and reassembly, inspection and servicing of basic engine parts, intake and exhaust system, lubrication system, cooling water system, remote control, electrical system, service standards, tightening torque for bolts and nuts
General Information:
Covers engine identification, specifications, and general service procedures.
Inspection and Adjustment:
Detailed procedures for routine inspections and adjustments.
Troubleshooting:
Diagnostic charts and step-by-step troubleshooting for common issues.
Disassembly and Reassembly:
Guidance on engine removal, disassembly, and reassembly.
Basic Engine Parts:
Inspection and servicing of major components like cylinder head, pistons, and bearings.
Intake and Exhaust System:
Service procedures for air intake, exhaust manifold, and related components.
Lubrication System:
Oil pump, filter, and lubrication circuit maintenance.
Cooling Water System:
Raw water pump, heat exchanger, and cooling system service.
Remote Control:
Adjustment and maintenance of remote control systems.
Electrical System:
Starter, alternator, wiring, and electrical troubleshooting.
Service Standards:
Specifications and tolerances for engine components.
Tightening Torque:
Torque values for bolts and nuts.
Technical Depth:
Intermediate to advanced; suitable for professional technicians and experienced DIY owners.
Parts Information:
Includes part numbers and specifications where applicable.
Procedures Included:
Step-by-step instructions with illustrations and specifications.
Applicability:
Yanmar 3YM30, 3YM20, 2YM15 and other YM series engines.
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 Options:
3YM30 (3-cylinder), 3YM20 (3-cylinder), 2YM15 (2-cylinder)
Displacement:
3YM30: 1.115 L; 3YM20: 0.854 L; 2YM15: 0.570 L
Bore and Stroke:
3YM30: 78 mm x 78 mm; 3YM20: 75 mm x 72 mm; 2YM15: 70 mm x 74 mm
Power Output:
3YM30: 29 hp (21.3 kW) at 3600 rpm; 3YM20: 20 hp (14.7 kW) at 3600 rpm; 2YM15: 14 hp (10.3 kW) at 3600 rpm
Torque:
N/A - not specified for this model
Fuel System:
Direct injection diesel
Cooling System:
Fresh water cooling with heat exchanger
Aspiration:
Naturally aspirated
Wheelbase:
N/A - not applicable for marine engines
Length:
3YM30: 620 mm; 3YM20: 580 mm; 2YM15: 520 mm
Width:
3YM30: 500 mm; 3YM20: 480 mm; 2YM15: 440 mm
Height:
3YM30: 620 mm; 3YM20: 600 mm; 2YM15: 580 mm
Dry Weight:
3YM30: 165 kg; 3YM20: 145 kg; 2YM15: 115 kg
Crash Test Ratings:
N/A - not applicable for marine engines
Active Features:
Engine alarms for low oil pressure, high coolant temperature, and low raw water flow.
Passive Features:
Emergency stop, guards on rotating parts.
Service Intervals:
Oil change: 100 hours or annually; fuel filter: 200 hours; impeller: annually.
Engine Oil:
API CD or better, SAE 15W-40 (depending on climate)
Coolant:
50/50 ethylene glycol antifreeze mix
Transmission Fluid:
Per marine gear manufacturer specifications
Known Issues:
Raw water pump impeller wear, exhaust elbow corrosion, fuel system air leaks.
Manufacturer:
Yanmar Co., Ltd.
Brand Heritage:
Yanmar is a Japanese engine manufacturer founded in 1912, known for diesel engines in marine, agricultural, and industrial applications.
Model Evolution:
The YM series replaced earlier Yanmar marine diesel engines, offering improved efficiency and emissions.
Production Location:
Japan
