Water Pump Impeller Kit – Fits Yamaha 2-Stroke 25–30 HP Outboard Engines (Replaces 689-W0078-A4-00, 689-W0078-04-00)

Water Pump Impeller Kit – Fits Yamaha 2-Stroke 25–30 HP Outboard Engines (Replaces 689-W0078-A4-00, 689-W0078-04-00)

Vendor: JLM Marine
Availability: In Stock
Product Type: Water Pump Impeller Kit
$28.95
$34.00
$28.95
Subtotal: $28.95

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Water Pump Impeller Kit – Fits Yamaha 2-Stroke 25–30 HP Outboard Engines (Replaces 689-W0078-A4-00, 689-W0078-04-00)

Water Pump Impeller Kit – Fits Yamaha 2-Stroke 25–30 HP Outboard Engines (Replaces 689-W0078-A4-00, 689-W0078-04-00)

$34.00 $28.95

Water Pump Impeller Kit – Fits Yamaha 2-Stroke 25–30 HP Outboard Engines (Replaces 689-W0078-A4-00, 689-W0078-04-00)

$34.00 $28.95

Water Pump Impeller Kit – Fits Yamaha 2-Stroke 25–30 HP Outboard Engines

This water pump impeller repair kit provides all the necessary components to restore the cooling system on select Yamaha 2-stroke 25 HP and 30 HP outboard engines. It is designed to meet or exceed original equipment specifications for a reliable, direct-fit installation.

This kit is a direct replacement for Yamaha outboard models including 25 HP (1986–1997) and 30 HP (1986–1992), covering C25, C30, CV25, and CV30 engine series. It also cross-references with parts for specific Mercury/Mariner models.

  • Installation Type: Direct replacement for a complete water pump overhaul.
  • Core Components: Includes impeller, housing, wear plate, gaskets, and hardware.
  • Materials: Features a marine-grade metal housing and a durable CR Neoprene Rubber impeller for longevity.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Brand Part Number
Yamaha 689-W0078-A4-00
Yamaha 689-W0078-04-00
Yamaha 689-W0078-06-00
Yamaha 689-W0078-A6-00
Yamaha 689-W0078-05-00
Sierra Marine 18-3426
Sierra Marine 18-3427
Mercury 47-42431M
Mercury 47-84829M
Mercury 47-97793M
Mercury 47-97793T
Mercury 47-81242M
Mercury 47-95661M

Compatible Engine Models

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

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.

Yamaha Outboards

Brand Model Rated HP Stroke Years OEM Part No.
Yamaha 25 25 2-Stroke 1986–1987 689-W0078-A4-00
Yamaha C25 25 2-Stroke 1991–1997 689-W0078-A4-00
Yamaha 30 30 2-Stroke 1986 689-W0078-A4-00
Yamaha C30 30 2-Stroke 1991–1992 689-W0078-A4-00
Yamaha CV25 25 2-Stroke 1990 689-W0078-A4-00
Yamaha CV30 30 2-Stroke 1989–1990 689-W0078-A4-00
Yamaha C25ELRU 25 2-Stroke 1996 689-W0078-A6-00
Yamaha C25ELRV 25 2-Stroke 1997 689-W0078-A6-00
Yamaha C25ELHU 25 2-Stroke 1996 689-W0078-A6-00
Yamaha C25ELHV 25 2-Stroke 1997 689-W0078-A6-00
Yamaha C25MLHU 25 2-Stroke 1996 689-W0078-A6-00
Yamaha C25MSHU 25 2-Stroke 1996 689-W0078-A6-00
Yamaha C25MLHV 25 2-Stroke 1997 689-W0078-A6-00
Yamaha C25MSHV 25 2-Stroke 1997 689-W0078-A6-00

Mercury/Mariner Outboards

Brand Model Rated HP Stroke OEM Part No. Notes
Mercury/Mariner 20C 20 2-Stroke 47-42431M Compatible replacement
Mercury/Mariner 25C 25 2-Stroke 47-84829M Compatible replacement
Mercury/Mariner 28 28 2-Stroke 47-97793M/47-97793T Compatible replacement
Mercury/Mariner 30A 30 2-Stroke 47-81242M/47-95661M Compatible replacement

Technical Specifications

Specification Value
Product Type Water Pump Impeller Repair Kit
Installation Direct replacement
Housing Material Marine-grade metal (housing), CR Neoprene Rubber (impeller)
Weight 236–285 g (8.4–10.1 oz)

Package Contents

  • 1 x Water Pump Impeller (689-44352-02-00)
  • 1 x Woodruff Key (664-44338-00-00)
  • 1 x Water Pump Housing (689-44311-03-00)
  • 1 x Insert Cartridge (689-W4432-01-00 / 689-W4432-02-00)
  • 1 x Wear Plate/Cartridge Outer Plate (689-44323-02-00 / 689-44323-03-00)
  • 1 x Cartridge Gasket (689-44324-A0-00)
  • 1 x Water Pump Gasket (689-44316-A0-00)
  • 1 x Water Seal Damper (626-44365-01-00 / 626-44365-02-00)
  • 3 x Bolt with Washer (97080-06030-00 / 90119-06M07-00)

Installation Guide

  1. Safety First: Disconnect the battery and ensure the engine is securely mounted.
  2. Access the Lower Unit: Drain the gearcase oil. Remove the bolts securing the lower unit (gearcase) to the upper engine housing.
  3. Remove the Old Pump: With the lower unit separated, locate and unbolt the water pump housing.
  4. Disassemble: Carefully remove the old housing, impeller, gaskets, and wear plate. Clean all mating surfaces thoroughly.
  5. Install New Components: Install the new wear plate, gaskets, and woodruff key on the driveshaft.
  6. Install Impeller: Slide the new impeller onto the driveshaft, turning the shaft clockwise to bend the vanes correctly.
  7. Install Housing: Lubricate the inside of the new insert cartridge and housing, then slide it down over the impeller.
  8. Reassemble: Secure the new housing with the provided bolts, torqued to manufacturer specifications.
  9. Reinstall Lower Unit: Guide the lower unit back into place, ensuring the driveshaft, shift shaft, and water tube align. Bolt it securely.
  10. Final Checks: Refill the gearcase with fresh oil. Reconnect the battery.
  11. Test Operation: Start the engine in the water or with a proper flushing attachment ("muffs") and confirm a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this fits my engine?
A: The most reliable method is to match your engine's model and year against the compatibility tables above. We also recommend using the provided model identification guides and part number cross-reference to verify a match before ordering.

Q: What are the common signs of a failing water pump impeller?
A: Key symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and in some cases, a faint burning rubber smell if the impeller has run dry and disintegrated.

Q: How often should I replace the water pump impeller?
A: As a general rule for preventative maintenance, it is recommended to inspect the impeller annually and replace 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.

We can ship to virtually any address in the world with free shipping available for most regions.

For our typical US and Canadian customers , our shipping timeframes are as follows:

  • Amazon FBA: orders will be delivered within 1-5 business days after placing the order (during certain special periods such as major promotions, Christmas, etc., the delivery time of Amazon FBA may be affected).
  • US warehouse shipment: orders will be delivered within 5 days after placing the order.
  • China warehouse shipment: orders will be delivered about 12 days after placing the order.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.

As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.

We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.

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