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Yanmar 4LH / 4LHA Engine Parts

Yanmar

4LH / 4LHA engine parts

4LH / 4LHA

Browse parts for Yanmar 4LH and 4LHA four-cylinder marine diesels. The complete model suffix, engine serial number and installed drive or marine gear are essential to selecting the correct service assembly.

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Service & maintenance

Start your parts search

Collections are browsing aids and include parts for other engines. Confirm the complete model, serial number and exact assembly before ordering.

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Browse by system

Find your service category

These broader collections help you browse. A category link does not confirm engine-specific compatibility.

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Before selecting parts

Identify the engine you have

Use the complete identification to select the correct generation, diagram and replacement part.

HTP / DTP / STP

Documented 4LHA-HTP, DTP and STP are 3.455-litre turbocharged, intercooled versions with distinct specifications. Earlier HTE, DTE and STE require their own catalogue selection.

Fuel-system distinction

HTP uses a VE rotary injection pump; DTP and STP use inline injection pumps in the documented specifications. Mechanical control does not establish fuel-system interchangeability.

Inboard & Z variants

HTP/DTP/STP inboard and HTZP/DTZP/STZP sterndrive versions are separately identified. Match cooling, exhaust and drive equipment to the actual version.

Original 4LH and 4LHA are distinct designations. Do not map regional 4LH-HT, UT or WST versions onto later 4LHA P-suffix engines automatically.

Send the complete engine-plate details and clear old-part photos. Match the installed fuel and cooling equipment, and include the separate drive or marine-gear plate when asking about those assemblies.

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Documented installations

Boat examples

These examples describe documented engine options or installations. Boats may have been repowered or modified; an example does not establish present-day parts compatibility.

Tideman RBB 900 2WJ Bow Console crew tender

The builder brochure specifies twin 4LHA-DTP engines with waterjets for this configuration. The adjacent Bow Cabin uses another engine.

Serial number help

Request a parts check

Send the Parts Desk the complete engine model and serial number, the OEM part number if known, and clear photos of the identification plate and old part. Include the installed fuel and cooling equipment when asking about those systems.

Include in your message

  • Complete engine model, suffix and serial number
  • OEM part number, if known
  • Identification-plate and old-part photos
  • Drive, transom or marine-gear identification for those parts

Parts Desk

Help before you order

Send your details through our contact page. The Parts Desk can help check the exact application before you select a replacement.

Ask the Parts Desk