Yanmar 4JH80

• Diesel

Save my engine

Troubleshooting

Starting problems

• Boat engine won't start after the winter
• Air in the fuel system – the diesel will not start
• Engine won't start
• Starter motor clicks or does not crank

Runs rough, stalls or loses power

• Boat engine dies at idle or when shifted into gear
• Boat engine hesitates or dies on acceleration
• The boat engine knocks or makes strange noises
• Boat engine stops after a while
• Boat engine does not reach full revs at full throttle

Smoke and exhaust

• The boat engine smokes blue – burning oil
• White smoke from the boat engine exhaust
• Diesel engine emits black smoke
• Engine smokes or loses power

Cooling and temperature

• Engine not cooling – weak or no cooling water
• Temperature alarm – engine overheating

Oil, water and fuel

• Water in the fuel or tank of the boat engine
• Water in the engine oil – the oil is grey or milky

Electrics, alarms and fault codes

• Battery not charging – charge warning light is on
• The alarm is sounding – what do the warning lights mean?
• Oil pressure alarm on the boat engine – low oil pressure

Drive, gearbox and trim

• Drive knocks or vibrates
• Gear will not engage or jumps out

Manuals

• Official

  Operation Manual JH series (3JH40/4JH45/4JH57/4JH80/4JH110) ↗ (external link)

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  EN · PDF

Exploded views & parts catalogs

• Shop

  Sextan: Yanmar manuals ↗ (external link)

  Dealers that publish Yanmar owner's manuals

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Service guides

Replacing the impeller →Winterize a boat engine →

Frequently asked questions about Yanmar 4JH80

Where can I find the owner's manual for Yanmar 4JH80?

Links to owner's manuals and workshop manuals are available under Manuals.

What fuel does the Yanmar 4JH80 use?

Yanmar 4JH80 runs on diesel.

Sources

• Yanmar: Operation Manual JH series (3JH40/4JH45/4JH57/4JH80/4JH110) ↗ (external link)
• Wikipedia: Yanmar ↗ (external link)
• Operation Manual 2GM20(F)/3GM30(F) (Yanmar, Osaka; archived copy) ↗ (external link)