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Raw Water Pump – Fits Yanmar 6LY2 Series Engines (Replaces 119574-42502)

Regular price $672.50

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Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.


If the return is due to our error or a defective item, we’ll make it right.


Please contact us before returning any item.

Delivery and Shipping

Orders are typically processed within 1–2 business days.


U.S. orders usually arrive within 6–15 days, depending on stock location and destination.


International delivery times may vary due to customs processing.


Tracking information will be provided once your order ships.

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This bronze construction Raw Water Pump – Fits Yanmar 6LY2 Series Engines is a direct-fit replacement designed for various Yanmar 6LY2 series diesel marine engines (315–440 HP). It serves as the main engine cooling pump, circulating sea water through the cooling system to maintain optimal operating temperatures.

This component directly replaces Yanmar part number 119574-42502 (which supersedes 119574-42500, 119574-42501, and 719574-42700) and Johnson part number 10-13170-01.

  • Designed for direct OEM replacement installation.
  • Self-priming pump design with a 15 ft suction lift capability when wet.
  • Features a heavy-duty bronze housing for superior corrosion resistance in marine environments.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number Notes
Yanmar 119574-42502 Supersedes 119574-42500, 119574-42501, 719574-42700
Johnson 10-13170-01 Direct cross-reference

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This pump is compatible with the following Yanmar 6LY2 series marine engines.

Brand Model Stroke OEM Part No.
Yanmar 6LY2-ST 4-Stroke 119574-42502
Yanmar 6LY2-STVY 4-Stroke 119574-42502
Yanmar 6LY2-WST 4-Stroke 119574-42502
Yanmar 6LY2-WDT 4-Stroke 119574-42502
Yanmar 6LY2-WDTZY 4-Stroke 119574-42502
Yanmar 6LY2M-WDT 4-Stroke 119574-42502
Yanmar 6LY2M-WST 4-Stroke 119574-42502
Yanmar 6LYA-STP 4-Stroke 119574-42502
Yanmar 6LYA-STE 4-Stroke 119574-42502
Yanmar 6LYA-UTE 4-Stroke 119574-42502
Yanmar 6LY2-STE 4-Stroke 119574-42502
Yanmar 6LY2A-STP 4-Stroke 119574-42502
Yanmar 6LY2A-UTP 4-Stroke 119574-42502

Technical Specs

Product Type
Raw Water / Sea Water Engine Cooling Pump
Installation
Direct OEM Replacement
Housing Material
Bronze
Impeller Material
Neoprene
Shaft Construction
3X series non-magnetic marine grade
Seal Type
Long life mechanical seal
End Covers
O-Ring sealed
Priming
Self-priming with 15 ft suction lift (when impeller is wet)
Product Dimensions
34.0 cm L x 22.0 cm W x 22.0 cm H
Weight
6.12 kg (13.5 lbs)

What’s in the Box

  • 1x Complete Raw Water Pump Assembly

Installation Notes

  1. Ensure the engine is completely cool and the battery is disconnected.
  2. Close the raw water intake seacock to prevent water from entering the vessel.
  3. Place a catch pan under the existing pump to manage any spilled coolant or water.
  4. Carefully loosen the hose clamps and detach the inlet and outlet hoses from the pump.
  5. Remove the mounting bolts securing the old pump to the engine block.
  6. Clean the engine mounting surface and inspect hoses for cracks or wear, replacing if necessary.
  7. Mount the new pump onto the engine, ensuring a flush fit. Torque bolts to manufacturer specs.
  8. Reconnect the hoses and tighten clamps securely.
  9. Open the seacock, reconnect the battery, and start the engine.
  10. Immediately check the pump and all connections for leaks.

Troubleshooting & FAQ

How do I know if my raw water pump needs to be replaced?

Common signs of a failing pump include engine overheating, a reduction in water flow from the exhaust, visible water leaks from the pump's weep holes or seals, and grinding or squealing noises from the pump assembly.

What maintenance does this pump require?

Regularly inspect for leaks. The internal neoprene impeller is a wear item and should be inspected at least once a year and replaced if you find cracks, stiffness, or missing vanes. Always follow your engine's service manual for recommended intervals.

Will this fit an engine other than a Yanmar 6LY2 series?

No. This pump is specifically engineered to fit the Yanmar 6LY2 series engines listed in the compatibility table. Using it on other models may lead to improper fitment, poor performance, or engine damage.

Is the impeller pre-installed?

Yes, the pump comes as a complete assembly with a new neoprene impeller installed and ready for installation.

Is this an OEM part?

This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

What are the shipping speed and cost?

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

What is the warranty and return policy?

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

  • Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement, not an OEM component.
  • Professional installation is recommended for safety and performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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