MarineDieselXRef
Home › Engines › 3YM20

3YM20 Marine

Yanmar 3YM20 · 3YM family: specifications, its industrial/tractor base engine, cross-referenced parts and where to buy them.

🚜 Base engine confirmed

The Yanmar 3YM20 is a Yanmar marine diesel in the 3YM20 family. Yanmar designs and sells both marine and industrial diesels; internal service parts for this family are listed in the 3YM20 parts book and often sell cheaper through industrial/agricultural channels than under marine dealer pricing. — Yanmar OEM parts catalog in-repo (brands/yanmar/data/extracted/catalogs.csv)

21 hp15.4 kW
854 ccdisplacement
70×74 mmbore × stroke
3-cylcylinders
110 kgengine dry
9.8 kggearbox
from 2004year range (approx)
NAaspiration

max 21mhp@3600 / cont @3489 (Yanmar 3YM20 datasheet)

📋 Full specifications 17 🚜 Industrial / tractor base 🔧 Aftermarket 60
Cheaper-part coverage · 4/8
🚜 Base engine ✓🌀 Impeller ✓💧 Raw-water pump🛢️ Oil filter⛽ Fuel filter🌡️ Thermostat ✓➰ Belt ✓⚓ Anode

A ✓ means at least one cheaper channel — aftermarket, the tractor/industrial base engine, or a standard component — exists for this engine in that category.

Parts by section · 47 assemblies

The exploded parts diagrams for the 3YM20, grouped by system. Open a figure for its callout part numbers and per-variant quantities.

Belts & pulleys

Fig 33 — COVER(V-BELT)

Bilge & accessory pumps

Fig 19 — BILGE PUMP(DELUXE)(OPTIONAL)(TO APR. 2004)Fig 38 — (19A)BILGE PUMP(OPTIONAL)(FROM MAR. 2004)

Camshaft & timing gears

Fig 2 — GEAR HOUSINGFig 9 — CAMSHAFT & DRIVING GEAR

Cooling – fresh water

Fig 14 — COOLING PUMP(FRESH WATER)Fig 15 — COOLER(FRESH WATER)Fig 17 — COOLING PIPE(FRESH WATER)

Cooling – sea water

Fig 13 — COOLING PUMP(SEA WATER)(TO E/#E13045)Fig 16 — COOLING PIPE(SEA WATER)Fig 43 — (13A)COOLING PUMP(SEA WATER)(FROM E/#E13046)

Cylinder block

Fig 1 — CYLINDER BLOCK

Cylinder head & valves

Fig 6 — CYLINDER HEAD & BONNET

Electrical & instruments

Fig 30 — STARTER MOTORFig 34 — WIRE HARNESS & RELAYFig 35 — INSTRUMENT PANEL(B-TYPE)(OPTIONAL)Fig 40 — INSTRUMENT PANEL(MEDALLION)(FROM JAN. 2012)Fig 45 — (34A)WIRE HARNESS (2-PANEL SPEC.)Fig 46 — (34B)ELECTRIC PARTS

Fuel injection pump & governor

Fig 20 — FUEL INJECTION PUMPFig 21 — GOVERNORFig 22 — FUEL FEED PUMP

Fuel injectors & nozzles

Fig 23 — FUEL INJECTION VALVE & FUEL INJECTION PIPE

Fuel lines, tank & filter

Fig 24 — FUEL PIPE & FUEL FILTERFig 25 — FUEL TANK(OPTIONAL)Fig 48 — (24A)WATER SEPARATOR

Gaskets, kits & spare parts

Fig 37 — GASKET SET(OPTIONAL)

Generator (genset)

Fig 31 — GENERATOR(HITACHI/60A)(UP TO SEP. 2010)Fig 32 — GENERATOR(HITACHI/80A)(UP TO E/#E11905)Fig 41 — (32A)GENERATOR(VALEO)(FROM E/#E11906)Fig 42 — COMBINATION OF GENERATOR, WIRE HARNESS, AND PANELFig 44 — (32B)GENERATOR(INNER PARTS)

Intake and Exhaust

Fig 7 — AIR INTAKE SILENCERFig 8 — MIXING ELBOW

Lubricating

Fig 3 — FLYWHEEL HOUSING & OIL SUMPFig 11 — DIPSTICKFig 12 — LUB. OIL SYSTEM

Mounting

Fig 4 — MOUNTING FOOTFig 18 — BILGE PUMP(STANDARD)(OPTIONAL)(TO APR. 2004)Fig 26 — BRACKET(CABLE)

Pistons, rods & liners

Fig 10 — CRANKSHAFT & PISTON

Tools & labels

Fig 5 — LABELFig 36 — TOOL

Transmission & drive

Fig 27 — CLUTCHFig 28 — CLUTCH REMOTE CONTROLFig 29 — COUPLING(OPTIONAL)Fig 47 — PROPELLER NUT
📚 Manuals & Sources
Specs— none yet
Operator's Manual— none yet
Service / Workshop Manual— none yet
Parts Catalog / List— none yet
More📖 Boat Inboard Engine Manuals Boat Manuals

External links — we host none of these documents.

3YM20 — Affiliate Parts Search

eBayAliExpress

eBay and AliExpress links are affiliate links. They help pay for the site, at no extra cost to you. More

Category
Marine
Engine family
3YM
Year range (approx)
from 2004
Cylinders
3
Rated output
21 hp (15.4 kW)
Bore × stroke
70 × 74 mm
Displacement
854 cc
Max rpm
3600
Continuous rpm
3489
Aspiration
Naturally aspirated
Dry weight (engine)
110 kg
Gearbox
9.8 kg
With standard gearbox
119.8 kg

Related 3YM engines

3YM303YM30AE