Yanmar Water Pump 129271-42503
$1,775.90 NZD incl. GST
In stockFreight calculated at checkout
- In business since 1927
- Backed by our Auckland workshop
- Capricorn preferred supplier
- Delivery across NZ and worldwide
Shipping & delivery
Freight is calculated at checkout by weight and volume. Orders over 25 kg or 2.5 m³: we'll email the freight cost after you order.
Standard delivery: 2–5 working days. Rural: 4–6 working days.
Click & Collect: we'll call to arrange a time at 77 Leonard Road, Mount Wellington, Auckland.
Outside New Zealand? Contact us for a freight quote.
Returns & warranty
Returns are handled under our refund policy. Your rights under the Consumer Guarantees Act are not affected.
For warranty claims, email sales@simmsdiesel.co.nz with proof of purchase and photos, and contact us before fitting a replacement. See warranty.
Product details
Marine raw water (seawater) pump designed for Yanmar 3JH4, 3JH5, 4JH4 and 4JH5 series diesel engines. This unit replaces older Yanmar part numbers and includes the hose-type port connection for the engine cooling system.
PART NUMBER
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129271-42503
✔ Replaces Older Yanmar Part Numbers:
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129271-42502 (primary superseded number)
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Also replaces: 129271-42500, 129271-42501
Equivalent Aftermarket / Johnson Pump Cross-References
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Replaces Johnson Pump part numbers 10-13328-01 and 10-13328-03 (common OEM substitutes).
Impeller & Consumables
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Yanmar impeller originally 129670-42530, which itself has been updated to 129670-42531 (verify exact fit for your engine).
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Johnson impeller equivalent: 09-1027B.
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Mounting gasket: Yanmar part 129150-01881 (required for correct installation, often sold separately).
Applicable Yanmar Engines
This pump is suitable for seawater cooling on the following engines and series:
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3JH4 / 3JH4E
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3JH5 / 3JH5E
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4JH4 / 4JH4E / 4JH4AE
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4JH5 / 4JH5E
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Also fits extended 4JH series variants such as 4JH45, 4JH57, 4JH80, 4JH110 (confirm exact model suffix before ordering).
Key Features
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Port Type: Hose connection for raw / seawater cooling system.
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Direct OEM or Equivalent Replacement: Designed to directly replace older Yanmar pumps with no major modifications.
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Heavy-duty marine design: Suitable for extended use in saltwater environments when installed with proper impeller and service parts.
Installation Notes
✅ Always replace the mounting gasket (129150-01881) when installing a new pump.
✅ Inspect and if necessary replace the impeller (129670-42531) during service.
✅ Check cross-references if using aftermarket brands (JMP, RECMAR, etc.) to ensure full compatibility.