Yamaha Water Pump Repair Kit – Fits Yamaha 25-30HP Outboards (61N-W0078-11-00, 61N-W0078-14-00)
This water pump repair kit is a direct-fit replacement for Yamaha 4-Stroke F25, F25A, & F25B (25HP) outboards from 1998–2017 and Yamaha 2-Stroke C30 (30HP) outboards from 1993–1997. It provides all necessary components to service and restore your engine's cooling system.
This kit replaces Yamaha OEM part numbers 61N-W0078-01-00, 61N-W0078-00-00, 61N-W0078-14-00, 61N-W0078-13-00, 61N-W0078-11-00, 61N-w0078-10-00, and Sierra aftermarket part 18-3432.
- Includes a new marine-grade metal alloy housing for a complete overhaul.
- All parts are designed for direct installation in the lower unit.
- Kit contains a new impeller, wear plate, cup, gaskets, and bolts required for assembly.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Yamaha |
61N-W0078-01-00 |
| Yamaha |
61N-W0078-00-00 |
| Yamaha |
61N-W0078-14-00 |
| Yamaha |
61N-W0078-13-00 |
| Yamaha |
61N-W0078-11-00 |
| Yamaha |
61N-W0078-10-00 |
| Sierra |
18-3432 |
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.
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| Yamaha |
F25 |
25 |
4-Stroke |
1998-2017 |
61N-W0078-11-00 |
F25A and F25B variants |
| Yamaha |
C30 |
30 |
2-Stroke |
1993-1997 |
61N-W0078-11-00 |
|
Technical Specifications
| Specification |
Value |
| Product Type |
Outboard Water Pump Repair Kit with Housing |
| Installation |
Lower Unit |
| Housing Material |
Marine-grade corrosion-resistant metal alloy |
| Housing Color |
Silver/Metallic |
| Weight |
238g (8.4 oz) |
| Fitting Type |
Direct fit to specified engines |
| Other Technical Attributes |
Includes housing for complete water pump service |
Package Contents
This kit includes the following components:
- 1 x Water Pump Impeller (6H4-44352-00)
- 1 x Key, Woodruff (90280-03M03-00)
- 1 x Housing, Water Pump (61N-44311-01-00)
- 1 x Cartridge Outer Plate (61N-44323-00-00)
- 1 x Insert Cup (61N-44322-01-00)
- 1 x O-Ring (9310-45161-00)
- 1 x Water Seal (6L2-44367-00-00)
- 4 x Bolt (97095-06040-00)
Installation Guide
Follow these steps for a successful installation. Ensure the engine is off and the battery is disconnected before beginning.
- Shift the outboard into the neutral position to ease lower unit removal.
- Carefully unbolt and detach the lower unit (gearcase) from the main engine housing.
- Locate and unbolt the existing water pump housing to access the old components.
- Remove the old impeller, woodruff key, wear plate, and any seals or gaskets, noting their orientation.
- Thoroughly clean all mating surfaces, removing any old gasket material or corrosion.
- Install the new gaskets, woodruff key, and impeller onto the driveshaft. Ensure the impeller vanes are oriented correctly (typically bent opposite the direction of shaft rotation).
- Fit the new insert cup and cartridge outer plate over the impeller.
- Slide the new water pump housing into place and secure it by tightening the four new bolts to the manufacturer's specified torque.
- Re-attach the lower unit to the outboard, ensuring all connections and shift linkages are correctly aligned.
- Once assembled, start the engine in water and verify a strong, steady stream of water is exiting the "tell-tale" outlet.
Troubleshooting & FAQ
How do I confirm this kit fits my engine?
First, check your engine's model, horsepower, and manufacturing year against our "Compatible Engine Models" table. Second, verify that your current part number matches one of the numbers listed in the "Part Number Cross-Reference" section. Visual comparison with our product photos is also recommended.
What are the signs of a failing water pump?
The most common signs are the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" cooling outlet, or discovering a cracked, brittle, or worn impeller during routine maintenance.
How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to inspect the water pump and replace the impeller at least every 1-2 years or every 100-200 hours of operation. Service intervals should be shorter for engines used frequently in saltwater or sandy/murky water conditions.
OEM vs. Aftermarket?
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.
How fast do you ship and how much does it cost?
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.
What is your warranty and return policy?
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.