Water Pump Impeller Repair Kit – Fits Mercury Mariner 25-30 HP 4-Stroke Outboard (Replaces 853792A1, 853792T01)

Water Pump Impeller Repair Kit – Fits Mercury Mariner 25-30 HP 4-Stroke Outboard (Replaces 853792A1, 853792T01)

This water pump impeller repair kit is designed for Mercury Mariner 25-30 HP 4-stroke outboards (2006 and newer) and a range of Tohatsu/Nissan 25-40 HP outboards. It provides all the necessary components for a complete water pump service to maintain your engine's cooling system.

This kit is a direct replacement for Mercury OEM part numbers 853792A1, 853792A07, and 853792T01, as well as Tohatsu/Nissan part numbers 361-87322-0, 361-87322-1, and 361-87322-2.

• Engineered as a direct OEM-quality replacement for straightforward installation.
• Restores cooling system performance to prevent overheating.
• Includes a complete set of gaskets, impeller, key, plate, and liner for a full service.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 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 Guide

Professional installation is recommended. The general steps below are for reference only.

1. Disconnect the battery and shift the outboard into neutral.
2. Remove the lower unit by unbolting it from the midsection. Disconnect the speedometer tube if present.
3. Place the lower unit on a workbench. Remove the bolts securing the water pump housing.
4. Slide the old housing and impeller off the driveshaft. Note the orientation of the old impeller vanes.
5. Clean the driveshaft and the mounting surfaces of the wear plate and housing.
6. Install the new wear plate and gasket.
7. Slide the new impeller key into the driveshaft keyway.
8. Lubricate the new impeller and housing interior with a marine-safe lubricant.
9. Install the new impeller onto the driveshaft, turning it clockwise to bend the vanes correctly.
10. Position the new housing and gasket, then tighten the bolts to the manufacturer's specified torque.
11. Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube align correctly.
12. Reconnect the battery and test the engine in a water source to confirm proper water flow.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my Mercury engine?

A: For Mercury and Mariner models, fitment is determined by the serial number (S/N). This kit fits 25 HP models with S/N 0N018456 and above, and 30 HP models with S/N 0N001875 and above. Please check the compatibility table and your engine's serial number plate before ordering.

Q: What are the signs that my water pump impeller needs replacing?

A: Common signs of a failing impeller include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and visible cracks or damage on the impeller vanes during inspection.

Q: How often should I replace the water pump impeller?

A: As a general maintenance guideline, we recommend inspecting the impeller annually and replacing it every 1-2 years or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).

Q: OEM vs. Aftermarket?

A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?

A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?

A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.