⚓ Working on this equipment?

Ask the AI troubleshooter, log your hours on board and turn them into invoice-ready service reports — for this exact model.

Start free — 14 days →

No credit card required

🔧 142 verified suppliers & service companies for Yanmar in the Maritime Network Find suppliers →

Is Yanmar your company? Claim this page

Yanmar

6N21L

Name: Yanmar 6N21L
Brand: Yanmar

Yanmar N-Series Marine Auxiliary Genset — Marinediesel, Bohrung 180 (6N18AL) / 210 (6N21AL) x Hub 280 (6N18AL) / 290 (6N21AL) mm, 720/750 or 900/1000 rpm, 6N18AL: 455-660 kW / 6N21AL: 745-1020 kW. Brennstoff: Marine Diesel Oil (MDO), Heavy Fuel Oil (HFO). Status: Discontinued (6N18AL-V/-SV/-EV/-UV/-HV series). 6N21AL-W series (DW/SW/EW/GW) current production. Verifiziert, Datenblatt verlinkt.

1500.0 kW

Power

Engine Specifications

Cylinders

210 mm

Bore

320 mm

Stroke

1,500 kW

MCR Power

900.0 rpm

MCR RPM

4-stroke

Stroke Type

Family: Yanmar 6EY26 · Tier: IMO Tier II · Fuel: HFO, MDO

Other Cylinder Configurations 8

Components & Design

Component data being added…

Technical Data

Displacement 6N18AL: 42.75L / 6N21AL: ~47L

Generator Capacity 6N18AL-SV: 662.5 KVA (560 kW) / 6N21AL-SV: 800 KVA (800 kW)

Compression Ratio 16.8:1

Oil Consumption <1.1 g/kWh

Exhaust Temperature ≤400°C

Configuration Vertical single-acting inline, 4-stroke, direct injection, compress air motor starting

unified from engine model True

🤖 Ask about this model

One free question — answered like a marine engineer. No account needed.

Common failures & inspection points

Turbocharger oil leakage causing intercooler clogging and boost pressure loss (documented symptom: <10% pressure drop indicates cleaning needed)

Inspect turbo seals, measure boost pressure, check intercooler for oil contamination

www.thehulltruth.com/boating-forum/...

Fuel injection system carbon deposits and water contamination causing injector blockage

Check fuel cleanliness, inspect injector nozzles for sludge, verify water separator function

www.atwildeplantparts.co.uk/blog/ho...

Seawater cooling system galvanic corrosion in coolers and cylinder head flange (exhaust valve area)

Check zinc anode wear, inspect cooler for corrosion pitting, examine cylinder head flange

www.cruisersforum.com/forums/f54/in...

Crankshaft journal ovality and cracks (documented case: 6N18AL-DV crank pin #4 with multiple cracks, 1.20mm undersizing required)

Measure crankshaft runout/ovality, visual crack inspection, check bearing clearances

www.marineengine.in/blog/2020/11/02...

Oil sludge accumulation from oxidation, water contamination, excessive idling reducing lubrication

Oil analysis for viscosity/water content, inspect oil cooler, verify change interval compliance

www.yammer.com/global/support/after...

Type-general inspection and maintenance points for this equipment category — not model-specific.

Suppliers & Spare Parts

Direct links to manufacturer, datasheet, spare-parts portal and dealers — request access below.

📄 Request sourcing links & documents

🛠 Manage this equipment in your fleet

Cases, daily reports, timesheets and AI troubleshooting in the OceanSphere Marine app — free for 14 days.

Start free trial →

🔎 Suppliers & service for this equipment

Find manufacturers, repair shops and spare-part dealers in the Maritime Network — our global company directory.

Maritime Network →

Equipment Model #38989 · ✓ still in production