Product line:
Marine diesel engines
20B TWO configuration:
0.635L two-cylinder vertical, 4-cycle, water-cooled
30B THREE configuration:
0.952L three-cylinder vertical, 4-cycle, water-cooled
Application:
Marine propulsion
Production years covered:
N/A - not specified for this model
Document type:
Service Repair Manual, Operator Manual and Parts Catalogue
Target audience:
Marine engine owners, mechanics and technicians
Intended use:
Operation, maintenance, repair and overhaul of Westerbeke marine diesels
Manual advantage:
Combines service, operator and parts information in one download
Diagnostic support:
Troubleshooting guides included for engine faults
Reference value:
Technical specifications, tightening torques and exploded views
Engine strengths:
Reliability and performance in demanding marine environments
Fuel system type:
Fuel injection pump with injection nozzle system
Charging:
Alternator charging system
Coverage:
Westerbeke 20B TWO and 30B THREE marine diesel engines
Manual type:
Service Repair Manual, Operator Manual and Parts Catalogue
Delivery:
Instant download
Page count:
N/A - not specified for this manual
Diagrams:
Exploded views with diagrams and pictures
Searchable text:
Standard for PDF manuals of this type
Engine overhaul:
Step-by-step overhaul procedures
Disassembly:
Engine disassembly procedures
Cylinder head:
Removal, inspection and repair
Gearcase:
Service and repair procedures
Timing gears:
Timing gear inspection and repair
Piston:
Piston removal, inspection and refitting
Connecting rod:
Connecting rod service
Governor system:
Governor adjustment and repair
Tightening torques:
Technical specification tables
Fuel, ignition and charging
Fuel injection pump:
Service and adjustment information
Injection nozzle:
Nozzle testing and repair
Glow plug system:
Starting aid diagnostics and service
Starter system:
Starter diagnosis and repair
Alternator system:
Charging system testing and repair
Diagnostics and reference
Troubleshooting guides:
Symptoms and corrective actions
Exploded views:
Component diagrams and pictures
Parts information:
Parts catalogue section with component identification
Operator information:
Operating and maintenance instructions
Technical specifications:
General and component specifications
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
Configuration:
Vertical, 4-cycle, water-cooled
Fuel system:
Fuel injection pump and injection nozzle
Ignition:
Glow plug and starter system
Configuration:
Vertical, 4-cycle, water-cooled
Fuel system:
Fuel injection pump and injection nozzle
Ignition:
Glow plug and starter system
Rated output:
N/A - not specified for this model
Rated speed:
N/A - not specified for this model
Standard transmission:
Marine gear (reduction/reversing) as installed by the vessel builder
Optional transmission:
N/A - not specified for this model
Engine-to-gear coupling:
Direct-mounted marine gear with damper plate
Reduction ratio:
N/A - depends on the marine gear fitted
Output flange:
N/A - depends on the marine gear fitted
Control:
Single-lever throttle and shift at helm station
Manual coverage:
Engine-side service information only; gear overhaul not covered
Wheelbase:
N/A - not applicable to a marine engine
Length:
N/A - not specified for this model
Width:
N/A - not specified for this model
Height:
N/A - not specified for this model
Curb weight:
N/A - not applicable; engine dry weight not specified for this model
Form factor:
Vertical inline marine diesel; fits marine engine beds via flexible mounts
Crash test ratings:
N/A - not applicable to a marine diesel engine
Shutdown protection:
Engine-mounted overheat and low oil pressure alarm switches where fitted
Cooling protection:
Raw water flow monitoring by exhaust discharge inspection
Starting safety:
Neutral start protection is provided by the vessel control system
Ventilation:
Engine compartment ventilation required for combustion air and heat removal
Fire risk:
Marine fuel system components and insulation to be inspected per vessel rules
Manual safety content:
Operator manual covers safe starting, shutdown and maintenance practice
Combustion:
Four-stroke water-cooled diesel with indirect fuel injection
Fuel metering:
Mechanical fuel injection pump and injection nozzles
Cold start:
Glow plug preheat with electric starter
Charging:
Belt-driven alternator for battery charging
Governing:
Mechanical governor system
Instrumentation:
Gauges and alarms supplied by the engine panel
Infotainment / audio:
N/A - not applicable to this engine
Driver assistance:
N/A - not applicable to this marine engine
Daily checks:
Coolant, oil and fuel levels; inspect for leaks and abnormal exhaust
Oil and filter change:
Per operating-hour schedule in the manual
Fuel filter service:
Replace at interval specified in the manual
Raw water impeller:
Inspect or replace at interval specified in the manual
Valve clearance:
Check and adjust at interval specified in the manual
Bleeding:
Fuel system bleeding procedure included in the manual
Engine oil grade:
N/A - not specified for this model
Oil capacity:
N/A - not specified for this model
Coolant specification:
N/A - not specified for this model
Fuel type:
Marine diesel fuel
Common wear items:
Impeller, filters, belts, glow plugs, injection nozzles and water pump
Known issues:
Hard starting from glow plug or fuel supply faults; overheating from raw water flow restriction
Heritage:
Long-established manufacturer of marine diesel engines and generators
Model evolution:
20B TWO and 30B THREE sit in the small two- and three-cylinder marine diesel range
Production location:
N/A - not specified for this model
Era:
N/A - not specified for this model
