Water Pump Repair Kit for Yamaha F15C and F20 4-Stroke Outboards – Replaces 6AH-W0078-00-00
Water Pump Repair Kit for Yamaha F15C and F20 4-Stroke Outboards – Replaces 6AH-W0078-00-00 is backordered and will ship as soon as it is back in stock.
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Water Pump Repair Kit for Yamaha F15C and F20 4-Stroke Outboards – ...
Water Pump Repair Kit for Yamaha F15C and F20 4-Stroke Outboards – Replaces 6AH-W0078-00-00 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Water Pump Repair Kit is designed to restore the cooling-water pump on selected Yamaha F15C and F20 four-stroke outboard engines. The water pump circulates cooling water through the engine; worn or damaged pump components can reduce water flow and contribute to overheating.
The kit is associated with Yamaha water pump repair kit references 6AH-W0078-00-00, 6AH-W0078-01-00, and 6AH-W0078-02-00. Sierra reference 18-3479 is also listed as an aftermarket cross-reference. Because Yamaha model codes, production years, and lower-unit configurations can differ, confirm the complete model code and the part number from your service manual before ordering.
- Installs in the outboard lower unit.
- Replaces worn water-pump service components to help restore cooling-water circulation.
- Suitable for selected Yamaha F15C and F20 four-stroke applications listed below.
- Aftermarket replacement; Yamaha and Sierra references are used for identification and compatibility comparison only.
Part Number Matrix
These references are provided to help compare the kit with the part number shown in your engine service documentation.
| Brand | Part Number | Reference Type |
|---|---|---|
| Yamaha | 6AH-W0078-00-00 | Water pump repair kit reference |
| Yamaha | 6AH-W0078-01-00 | Water pump repair kit reference |
| Yamaha | 6AH-W0078-02-00 | Water pump repair kit reference |
| Sierra | 18-3479 | Aftermarket cross-reference |
Engine & Model Compatibility
The catalog evidence available for these references identifies Yamaha F15C and F20 four-stroke applications. Fitment depends on the complete model code and model year, so use the table as a guide and verify your engine identification before installation.
| Brand | Model Family | Rated HP | Stroke | Documented Examples | Related Reference |
|---|---|---|---|---|---|
| Yamaha | F15C | 15 | 4-Stroke | F15CELH, F15CESH, F15CMLH, F15CMSH, F15CPLH; 2007 catalog examples | 6AH-W0078-00-00 |
| Yamaha | F15C / F15L variants | 15 | 4-Stroke | Selected F15LEHA, F15LMHA, F15LPHA, F15SEHA, and F15SMHA applications are documented with later suffix references; verify year and model code | 6AH-W0078-01-00 or 6AH-W0078-02-00 |
| Yamaha | F20 | 20 | 4-Stroke | F20ELH, F20ELR, F20ESH, F20ESR, and F20MLH; 2007 catalog examples | 6AH-W0078-00-00 |
Important: The available evidence does not establish universal fitment for every F9.9, F13.5, F15, or F20 engine. The former F9.9 and F13.5 claims have therefore been removed. Match the full model designation and year, not horsepower alone.
Technical Specifications
- Product Type
- Water Pump Repair Kit
- Application
- Selected Yamaha F15C and F20 4-Stroke outboard engines
- Installation Location
- Lower unit / water pump assembly
- Product Status
- Aftermarket replacement part
What’s in the Box
The listed kit contents are intended for servicing the water-pump assembly. Compare the components with your original parts before installation.
- 1 x Water Pump Housing (6AH-44311-00-00)
- 1 x Cartridge Insert (63V-44322-00-00)
- 1 x Water Seal Damper (6L2-44367-00-00)
- 1 x Impeller (63V-44352-01-00)
- 1 x Woodruff Key (664-44338-00-00)
- 1 x O-Ring (93210-49046-00)
- 1 x Cartridge Outer Plate (68T-44323-00-00)
- 2 x Dowel Pins (93604-10M03-00)
- 4 x Bolts (97095-08045-00)
- 2 x Plates (63V-44328-01-00)
Installation Notes
- Disconnect the battery and follow the safety instructions in the engine service manual.
- Place a drain pan beneath the lower unit and drain the gearcase lubricant as required by the service procedure.
- Remove the hardware securing the lower unit to the upper casing.
- Lower and separate the lower unit carefully, paying attention to the driveshaft, shift shaft, and water-tube connections.
- Remove the water-pump cover or housing and retain the parts needed for comparison.
- Clean the mating surfaces and remove the old impeller, key, seals, plates, and gaskets as applicable.
- Install the replacement components in the order specified by the service manual. Lubricate seals only with a product compatible with the material and application.
- Install the impeller with the vanes oriented according to the direction of driveshaft rotation and the manufacturer’s procedure.
- Reassemble the water-pump housing and tighten fasteners to the manufacturer’s specified torque.
- Reinstall the lower unit while aligning the driveshaft, shift shaft, and water tube.
- Refill the gearcase with the correct lubricant and quantity before operating the engine.
- Run the engine only with an appropriate water supply and confirm a steady tell-tale stream and normal operating temperature.
Troubleshooting & FAQ
How can I confirm that this kit fits my engine?
Check the complete Yamaha model code, model year, and the water-pump part number in your service manual. F15C and F20 horsepower labels alone are not sufficient because different model variants can use different water-pump references.
What are the signs of a failing water-pump impeller?
Common signs include a weak or missing tell-tale stream, overheating warnings, higher-than-normal operating temperature, or visibly cracked, hardened, or damaged impeller vanes. Always investigate restricted passages, damaged seals, and other cooling-system faults as well.
How often should the water pump be serviced?
Follow the maintenance schedule for your specific Yamaha engine. Inspect the impeller and related pump components more frequently when operating in saltwater, shallow water, sand, or silt. Replace parts that show wear, deformation, cracking, or loss of flexibility.
Is this an OEM part?
No. This listing is for an aftermarket replacement water pump repair kit. Yamaha and Sierra names and part numbers are shown only as identification and cross-reference information.
Does the kit fit every Yamaha F15 or F20?
No universal fitment should be assumed. Confirm the complete model code, year, and reference number before ordering; model family, shaft configuration, and production-year changes may affect compatibility.
Safety & Important Information
- Verify the model code, year, original part, and kit contents before installation.
- Do not operate the outboard without an adequate water supply.
- Use the service manual for torque values, gearcase procedures, alignment instructions, and safety requirements.
- Improper water-pump installation can cause inadequate cooling and serious engine damage.
- Professional installation by a qualified marine technician is recommended when the lower unit or cooling system is unfamiliar.
About Sea Sierra
- Marine Replacement Parts — We provide aftermarket components for common outboard maintenance and repair applications.
- Application-Focused Information — Product references and fitment guidance are presented to help customers compare their original parts and engine documentation.
- Service Support — Always use the engine manufacturer’s service information for final compatibility, installation, and maintenance decisions.
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