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Water Pump Impeller Repair Kit – Fits Mercury/Mariner 25-30 HP, Tohatsu/Nissan 25-40 HP (Replaces Mercury 853792A1, Tohatsu 361-87322-0)

Sale price $39.98 Regular price $63.00
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Water Pump Impeller Repair Kit – Fits Mercury/Mariner 25-30 HP, Tohatsu/Nissan 25-40 HP (Replaces Mercury 853792A1, Tohatsu 361-87322-0) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

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 comprehensive Water Pump Impeller Repair Kit – Fits Mercury Mariner 25-30 HP 4-Stroke Outboard (Replaces 853792A1, 853792T01) includes all necessary components to service your outboard's raw sea water pump. It is engineered for Mercury and Mariner 25 HP and 30 HP 4-stroke outboards manufactured from 2006 onwards, as well as a wide array of Tohatsu and Nissan 25 HP to 40 HP models.

This kit serves as a direct replacement for Mercury interchange parts 853792A1, 853792A07, and 853792T01, and Tohatsu/Nissan equivalents 361-87322-0, 361-87322-1, and 361-87322-2.

  • Designed for direct OEM-spec installation without modifications.
  • Built to withstand demanding raw sea water environments.
  • Includes the impeller, gaskets, housing insert, guide plate, and key for a complete service.

Part Number Matrix

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

Brand Part Number
Mercury 853792A1
Mercury 853792A07
Mercury 853792T01
Tohatsu/Nissan 361-87322-0
Tohatsu/Nissan 361-87322-1
Tohatsu/Nissan 361-87322-2

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury and Mariner engines, it is critical to verify your model, year, and serial number (S/N) range. This kit's compatibility begins with S/N 0N018456 for 25HP models and S/N 0N001875 for 30HP models.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Mercury 25 HP 25 4-Stroke 2006 and newer 853792A1/853792A07/853792T01 S/N 0N018456 and above
Mercury 25 HP Sea Pro 25 4-Stroke 2006 and newer 853792A1/853792A07/853792T01 S/N 0R051710 and above
Mercury 25 HP EFI 25 4-Stroke 2006 and newer 853792A1/853792A07/853792T01 S/N 0R106999 and above
Mercury 25 HP EFI JET 25 4-Stroke 2006 and newer 853792A1/853792A07/853792T01 S/N 0R165086 and above
Mercury 30 HP 30 4-Stroke 2006 and newer 853792A1/853792A07/853792T01 S/N 0N001875 and above
Mercury 30 HP EFI 30 4-Stroke 2006 and newer 853792A1/853792A07/853792T01 S/N 0R106999 and above

Fits various Tohatsu and Nissan 4-stroke models from 25 HP to 40 HP. Please verify your model against the list below.

Brand Model Rated HP Stroke OEM Part No.
Tohatsu/Nissan NS25C2, NS25C3, M25C2, M25C3, M25H, MX25H 25 4-Stroke 361-87322-0/361-87322-1/361-87322-2
Tohatsu/Nissan NS30A3, NS30A4, M30A3, M30A4, M30H, MX30H 30 4-Stroke 361-87322-0/361-87322-1/361-87322-2
Tohatsu/Nissan NS35C, M35C 35 4-Stroke 361-87322-0/361-87322-1/361-87322-2
Tohatsu/Nissan NS40C, NS40C2, M40C 40 4-Stroke 361-87322-0/361-87322-1/361-87322-2

Technical Specs

Product Type
Water Pump Impeller Repair Kit
Installation
Direct OEM replacement
Other Technical Attributes
Raw sea water pump repair service impeller kit

What’s in the Box

  • 1 x Water Pump Impeller (345-65021-0, 47-16154-1, 161541)
  • 1 x Impeller Key (332-65022-0)
  • 1 x Gasket (348-65029-1)
  • 1 x Gasket (348-65018-0)
  • 1 x Insert (348-65011-0)
  • 1 x Guide Plate (348-65025-0)
  • 4 x Bolts & Washers (910103-5652)

Installation Notes

  1. Disconnect the negative battery cable and remove the upper engine cowling.
  2. Disconnect the shift linkage from the engine.
  3. Remove the mounting bolts securing the lower unit (gearcase) to the engine leg and carefully lower it.
  4. Unscrew the bolts on the water pump housing and lift it off to expose the impeller.
  5. Remove the old impeller, key, gaskets, and wear plates, noting their orientation.
  6. Clean all mating surfaces of debris and corrosion. Inspect the housing for cracks or warping.
  7. Install the new gasket, guide plate, and housing insert.
  8. Slide the new impeller key into the driveshaft keyway and install the new impeller, turning the shaft clockwise to seat the vanes correctly.
  9. Reinstall the housing and torque the bolts to the manufacturer's specification.
  10. Re-attach the lower unit to the engine, reconnect the shift linkage, and test operation in water, ensuring a strong tell-tale stream.

Troubleshooting & FAQ

How do I know if this kit fits my specific Mercury series engine?

Check your engine's serial number (S/N), typically found on a tag on the transom bracket. This kit is compatible with 25 HP models with S/N 0N018456 and newer, and 30 HP models with S/N 0N001875 and newer. Refer to our compatibility table for more detailed model and S/N information.

What are the signs of a failing water pump impeller?

Common signs of a worn or damaged impeller include the engine overheating at idle or low speeds, a weak or intermittent "tell-tale" water stream from the exhaust port, or finding brittle, cracked, or melted rubber pieces upon inspection.

How often should this water pump kit be replaced?

As a crucial part of preventative maintenance, it is recommended to inspect the impeller annually and replace the entire kit every 1-2 years or every 100-200 hours of operation, whichever comes first. Usage in saltwater or sandy/silty conditions may require more frequent changes.

Is the impeller key (Woodruff key) included?

Yes, this is a complete service kit. It includes the impeller, impeller key (part no. 332-65022-0), housing insert, guide plate, all necessary gaskets, and mounting bolts with washers.

My Tohatsu model is listed, but a specific year isn't. How can I confirm fitment?

Because year ranges for some Tohatsu/Nissan models can vary, the best practice is to visually compare your existing impeller, gaskets, and housing components to the detailed parts shown in our product images. Matching the OEM part numbers listed also helps ensure compatibility.

OEM vs. Aftermarket?

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

Shipping speed & cost

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

Warranty & returns

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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