Yamaha Water Pump Impeller Repair Kit 6H4-W0078-A0 with Housing for 25 40 50 HP Outboard
Yamaha Water Pump Impeller Repair Kit 6H4-W0078-A0 with Housing for 25 40 50 HP Outboard
Product Overview
Yamaha water pump impeller repair kit with housing for 25 HP, 40 HP and 50 HP two-stroke outboards. It replaces Yamaha 6H4-W0078-00-00, 6H4-W0078-01-00 and 6H4-W0078-A0-00 and matches Sierra 18-3408, and the housing supplied inside the kit carries OE number 663-44311-02. The 13-piece kit includes the impeller, housing, insert cup and wear plate, so the whole pump can be rebuilt in one job. A worn impeller shows up as a weak tell-tale stream, rising head temperature at idle or rubber debris in the pump housing.
Specifications & Attributes
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Water Pump Impeller Repair Kit with Housing |
| Engine Type | Yamaha 2-stroke outboard |
| Horsepower Covered | 25 HP, 40 HP, 50 HP |
| Model Years | 1984-1995 |
| Housing OE | 663-44311-02 |
| Components | 13 pieces |
| Packaging | 15 x 10 x 5 cm (5.9 x 3.9 x 2.0 in) |
OEM Cross Reference
| Component | OEM Part Numbers |
|---|---|
| Yamaha — Kit | 6H4-W0078-00-00, 6H4-W0078-01-00, 6H4-W0078-A0-00 |
| Yamaha — Impeller | 6H4-44352-01, 676-44352-01 |
| Yamaha — Housing | 663-44311-02 |
| Yamaha — Housing (cast) | 663-44311 |
| Yamaha — Insert Cup (Stainless Bowl) | 663-44322-00 |
| Yamaha — Wear Plate (Stainless) | 663-44323 |
| Sierra | 18-3408 |
Compatible Engines
Fits the following Yamaha two-stroke outboards:
| Horsepower | Models | Years |
|---|---|---|
| 25 HP | 25Q, 25QEO | 1990-1994 |
| 40 HP | 40N, 40H, 40HE | 1984-1995 |
| 50 HP | 40N, 40H, 40HE | 1984-1994 |
What's Included
| Component | Qty |
|---|---|
| Water Pump Impeller | 1 |
| Insert Cup | 1 |
| Wear Plate | 1 |
| Pump Housing | 1 |
| Drive Key | 1 |
| Gaskets | 3 |
| Oil Seal | 1 |
| Bolts and Washer | 4 |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Before You Buy
- Verify your engine model or serial number before ordering
- Fits Yamaha 25Q, 25QEO, 40N, 40H and 40HE outboards
- Kit includes the housing, so no separate casting purchase is needed
- Lubricate the impeller with soapy water before fitting
- 30-Day Easy Returns
- Free Worldwide Shipping
- OEM Quality Without the Markup
Couldn't load pickup availability
Boat Owners' Review
Before You Buy
Frequently Asked Questions
What is your refund policy?
We offer a 14-day hassle-free return on all products. Items must be unused and in original packaging. Every XRmarine part is also covered by our 1-year warranty against manufacturing defects. If something is not right, email us at info@xrmarineparts.com — replacement or full refund, your choice.
See our full Refund Policy for complete details.
How does shipping work?
Free international shipping on every order — no minimums. We operate a global warehouse network with a main distribution centre in Asia (10-20 business days). We also hold stock in regional warehouses across the United States, Germany, the United Kingdom, Australia, and Poland (opening soon) — most orders arrive in 1-3 business days within those countries and in 2-8 business days to nearby regions. Tracking included.
See our full Shipping Policy.
How do you keep prices fair?
We cut out the middlemen. XRmarine sources directly from quality manufacturers and sells at honest prices. Same OEM-quality parts, no dealership markup. Every order comes with free shipping, real expert support, and a 1-year warranty.
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