Yamaha Water Pump Repair Kit with Housing – 40/50 HP 2-Stroke and F40/F50/F60 4-Stroke
Yamaha Water Pump Repair Kit with Housing – 40/50 HP 2-Stroke and F40/F50/F60 4-Stroke is backordered and will ship as soon as it is back in stock.
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Yamaha Water Pump Repair Kit with Housing – 40/50 HP 2-Stroke and F...
Yamaha Water Pump Repair Kit with Housing – 40/50 HP 2-Stroke and F40/F50/F60 4-Stroke is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump repair kit with housing is designed for selected Yamaha 40 HP and 50 HP 2-stroke outboards, plus selected F40, F50, and F60 4-stroke models. It provides the main components needed to service the water pump and renew the impeller, wear surface, seals, gaskets, fasteners, and pump housing.
The kit is listed for Yamaha reference numbers 63D-44311-00-00, 63D-W0078-00-00, 63D-W0078-01-00, 63D-W0078-02-00, and 63D-W0078-03-00. Sierra catalog references 18-3415 and 18-3434 identify comparable water-pump service configurations; verify the exact engine model and year before ordering.
- Complete water pump service kit with replacement housing.
- Includes an impeller, wear plate, insert cup, key, gaskets, seals, O-ring, cover, housing, washers, and fasteners.
- Suitable for listed Yamaha gasoline outboards in both 2-stroke and 4-stroke configurations.
- Aftermarket replacement part; Yamaha and Sierra names and numbers are used only for identification and fitment reference.
Reference Numbers
| Brand or catalog | Reference number | Use |
|---|---|---|
| Yamaha | 63D-44311-00-00 | Water pump housing reference |
| Yamaha | 63D-W0078-00-00 | Water pump repair-kit reference |
| Yamaha | 63D-W0078-01-00 | Water pump repair-kit reference |
| Yamaha | 63D-W0078-02-00 | Reference listed for this kit |
| Yamaha | 63D-W0078-03-00 | Reference listed for this kit |
| Sierra | 18-3415 | Comparable kit with housing |
| Sierra | 18-3434 | Comparable repair-kit reference |
Engine Compatibility
The company fitment records identify the following Yamaha engine families and year ranges. Model suffixes, shaft lengths, serial ranges, and regional variations may affect fitment, so compare the complete engine model designation and existing pump-part numbers before purchase.
| Brand | Engine model or family | Horsepower | Stroke | Years listed |
|---|---|---|---|---|
| Yamaha | 40, C40 | 40 HP | 2-Stroke | 1998–2003 |
| Yamaha | P40, 50, C50, P50 | 40–50 HP | 2-Stroke | 1997–2023 |
| Yamaha | F40 | 40 HP | 4-Stroke | 1999 |
| Yamaha | F50 | 50 HP | 4-Stroke | 1997–2023 |
| Yamaha | F60 | 60 HP | 4-Stroke | 2002–2023 |
Technical Specifications
- Product type
- Water pump repair kit with housing
- Application
- Selected Yamaha outboard cooling-system service
- Engine type
- Selected 2-stroke and 4-stroke gasoline outboards
- Installation
- Replacement water-pump service component
- Housing included
- Yes
- Manufacturer status
- Aftermarket replacement; not a Yamaha genuine part
What’s in the Box
One complete water pump service kit with housing, including the following components:
- 1 × Water pump housing — reference 63D-44311-00-00
- 1 × Water pump housing cover — reference 63D-44312-00-00
- 1 × Impeller
- 1 × Wear plate
- 1 × Insert cup
- 1 × Impeller key
- 1 × Water pump case gasket
- 1 × Water seal
- 1 × O-ring
- 1 × Bolt set containing 4 bolts
- 4 × Bolt washers
Component appearance and component-brand markings may vary by production batch. Confirm the parts against your original water-pump assembly before installation.
Installation Notes
- Disconnect the battery and remove the engine cowling according to the engine service procedure.
- Place the outboard securely and remove the lower unit.
- Remove the existing water-pump cover, impeller, key, plate, cup, housing, gaskets, seals, and related fasteners.
- Clean all mating surfaces and inspect the driveshaft, water tube, keyway, and surrounding components for wear or corrosion.
- Install the new gasket, plate, insert cup, impeller key, impeller, seals, O-ring, cover, housing, washers, and bolts in the correct service-manual order.
- Apply suitable lubricant to the impeller only where specified by the engine manufacturer, and orient the impeller vanes in the direction required during installation.
- Torque fasteners to the Yamaha service-manual specification for the exact engine model.
- Reinstall the lower unit, reconnect the battery, and test the engine in an appropriate water source.
- Confirm a steady tell-tale stream and verify that the engine does not overheat before returning it to service.
Professional installation is recommended. Always follow the service manual for the exact model, year, shaft configuration, and serial range.
Maintenance and Troubleshooting
What are common signs of a failing water-pump impeller?
A weak or intermittent tell-tale stream, overheating at idle or low speed, a temperature alarm, or damaged and brittle impeller vanes can indicate water-pump wear. Stop the engine if overheating occurs and inspect the cooling system.
How often should the impeller be serviced?
Inspect the water pump during routine maintenance and replace the impeller according to the engine manufacturer’s service schedule. Frequent operation in sandy, silty, or corrosive water can require more frequent service.
Does this kit include the water-pump housing?
Yes. The company product record identifies this product as a water pump service kit with housing. The kit includes the housing as well as the cover and other listed service components.
Can I use only the impeller from this kit?
The kit is supplied as a complete water-pump service kit. If only an impeller is needed, compare the impeller and keyway with the exact engine application before purchasing a separate component.
How do I confirm fitment?
Compare your complete Yamaha engine model, horsepower, stroke, year, shaft configuration, and existing water-pump reference with the information above. Do not rely on horsepower alone, because different engine families can use different pump assemblies.
Is this an OEM Yamaha part?
No. This is an aftermarket replacement kit. Yamaha reference numbers are provided only to help identify the applicable water-pump assembly.
Safety and Important Information
- Verify the complete engine model and year before ordering.
- Do not operate an outboard that shows signs of overheating or has no tell-tale water flow.
- Use the exact torque values, sealants, lubricants, and installation sequence specified in the engine service manual.
- Inspect the water tube, driveshaft, keyway, pump base, and mating surfaces while the lower unit is removed.
- Yamaha and Sierra trademarks and part numbers belong to their respective owners and are used for identification only.
About Sea Sierra
- Marine Replacement Parts — Practical aftermarket components for routine outboard maintenance and repair.
- Fitment-Focused Listings — Product information is organized around engine model, horsepower, stroke, and year conditions.
- Service-Ready Solutions — Kits combine the listed water-pump service components to simplify standard maintenance.
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