Model:
4BY and 6BY series marine diesel engines
Model Variants:
4BY series: 4BY150, 4BY180, 4BY220, 4BY260; 6BY series: 6BY220, 6BY260, 6BY310, 6BY350
Production Years Covered:
2005-2015
Engine Type:
Four-stroke, water-cooled marine diesel, direct injection
Manual Type:
Workshop Manual (Service and Repair)
Delivery Method:
Instant download after purchase
Binding:
Digital (no physical binding)
Target Audience:
Marine technicians, boat owners, and DIY mechanics performing maintenance or repairs on Yanmar 4BY and 6BY engines.
Competitive Advantage:
Covers both 4-cylinder and 6-cylinder BY series engines in a single manual; includes detailed step-by-step procedures and factory specifications not found in generic marine engine guides.
Key Features:
Comprehensive coverage of engine overhaul, fuel injection, cooling, and electrical systems; many illustrations and diagrams; troubleshooting charts.
Format:
PDF (digital download)
Delivery:
Instant download
Page Count:
N/A - not specified for this product
Manual Type:
Workshop manual for service and repair
Coverage Areas:
Engine mechanical, fuel system, cooling system, lubrication system, electrical system, troubleshooting, specifications
Applicable Models:
Yanmar 4BY and 6BY series marine diesel engines
Publication:
Based on factory service information
Engine Mechanical:
Cylinder head, valve train, cylinder block, pistons, connecting rods, crankshaft, bearings, timing gears
Fuel System:
Fuel injection pump, injectors, fuel filters, fuel lines, governor
Cooling System:
Sea water pump, fresh water pump, heat exchanger, thermostat, cooling passages
Lubrication System:
Oil pump, oil filter, oil cooler, relief valves, oil passages
Electrical System:
Alternator, starter motor, wiring diagrams, sensors, gauges
Turbocharger:
Inspection, removal, installation, and overhaul (for turbocharged models)
Diagnostic:
Troubleshooting charts and fault code retrieval (where applicable)
Disassembly:
Step-by-step engine removal and disassembly
Inspection:
Component inspection and measurement procedures with wear limits
Assembly:
Reassembly and installation with torque specifications
Adjustment:
Valve clearance, injection timing, belt tension
Testing:
Compression test, oil pressure test, cooling system pressure test
Specifications:
Complete torque specs, clearances, and wear limits
Illustrations:
Detailed diagrams and exploded views
Schematics:
Electrical wiring diagrams
Special Tools:
List of required special tools with part numbers
Component Identification:
Part names and numbers for ordering
Exploded Views:
Visual breakdown of assemblies
Service Kits:
Recommended service parts and intervals
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
4BY Series:
4-cylinder, 2.2L displacement, naturally aspirated and turbocharged versions, ratings from 150 hp to 260 hp
6BY Series:
6-cylinder, 3.3L displacement, turbocharged and turbocharged/intercooled versions, ratings from 220 hp to 350 hp
Power Range:
150-350 hp depending on model
Aspiration:
Naturally aspirated, turbocharged, or turbocharged with aftercooler
Cooling:
Fresh water (closed) cooling with heat exchanger
Emissions:
Compliant with EPA Tier 2 and EU Stage II (varies by year)
Injection Pump:
Mechanical or electronic (depending on model)
Governor:
Mechanical or electronic
Fuel Filter:
Primary and secondary filtration
Wheelbase:
N/A - not applicable to marine engines
Length:
Approx. 1,200 mm (4BY), 1,500 mm (6BY) including transmission (varies by configuration)
Curb Weight:
Approx. 350 kg (4BY), 500 kg (6BY) dry weight (varies by options)
Ratings / Crash Test:
N/A - not applicable to marine engines
Active Features:
Overheat alarms, low oil pressure alarms, overspeed protection (where equipped)
Passive Features:
Engine guards, insulated exhaust components (application dependent)
Oil Change:
Every 250 hours or annually
Fuel Filter:
Every 500 hours or annually
Coolant:
Check every 250 hours, replace every 2 years
Valve Clearance:
Check/adjust every 1000 hours
Impeller:
Inspect/replace every 500 hours or annually
Engine Oil:
API CF or higher, SAE 15W-40 (depending on climate)
Coolant:
Ethylene glycol-based marine coolant (50/50 mix)
Transmission Fluid:
Per marine gear manufacturer specifications
Common Wear Items:
Impeller, exhaust elbow, injectors, fuel lift pump
Common Issues:
Cooling system corrosion, fuel contamination, turbocharger wear (on high-hour engines)
