Water Pump Repair Kit with Housing – Fits Yamaha T25, F30 & F40 Outboards (Replaces 66T-W0078-00)
Water Pump Repair Kit with Housing – Fits Yamaha T25, F30 & F40 Outboards (Replaces 66T-W0078-00) is backordered and will ship as soon as it is back in stock.
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Water Pump Repair Kit with Housing – Fits Yamaha T25, F30 & F40...
Water Pump Repair Kit with Housing – Fits Yamaha T25, F30 & F40 Outboards (Replaces 66T-W0078-00) 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 select Yamaha T25, F30 and F40 outboard applications. It replaces the Yamaha water pump kit reference 66T-W0078-00 and is intended for water pump service and cooling-system maintenance.
Catalog fitment identifies this kit for Yamaha T25 models from 2001–2004, F30 models from 2001–2004, and F40 models from 2000–2004. Confirm the exact model, year and original part number before ordering.
- Complete water pump repair kit supplied with the pump housing.
- Includes the impeller, wear plate, gasket, key, insert cup, seals, O-ring, housing cover, washers and mounting bolts listed below.
- Designed as an aftermarket replacement for servicing the outboard water pump assembly.
Part Number References
Use these references to compare the kit with your existing water pump assembly. Part-number references do not replace model and year verification.
| Brand or Catalog | Reference | Application Note |
|---|---|---|
| Yamaha | 66T-W0078-00 | Replacement water pump kit reference |
| Sierra catalog | 18-3413 | Water pump kit with housing reference |
Engine & Model Compatibility
The following applications are identified for this water pump repair kit with housing. Model-year and component variations may apply, so verify your complete engine designation and original part number before installation.
| Brand | Model | Rated HP | Years | Stroke | Replacement Reference |
|---|---|---|---|---|---|
| Yamaha | T25 | 25 | 2001–2004 | Not specified in the source fitment | 66T-W0078-00 |
| Yamaha | F30 | 30 | 2001–2004 | 4-Stroke | 66T-W0078-00 |
| Yamaha | F40 | 40 | 2000–2004 | 4-Stroke | 66T-W0078-00 |
Technical Specifications
- Product Type
- Water pump repair kit with housing
- Installation
- Replacement water pump service component
- Housing Included
- Yes
- Primary Function
- Outboard cooling-system water circulation
- Kit Contents
- Impeller, plate, gasket, key, insert cup, housing, cover, seals, O-ring, washers and bolts
What's in the Box
- 1 x Water Pump Case Gasket (63D-44316-00-00)
- 1 x Impeller (6H4-44352-00-00)
- 1 x Impeller Plate / Wear Plate (66T-44323-00-00)
- 1 x Impeller Key (90280-03M03-00)
- 1 x Insert Cup (63D-44322-00-00)
- 1 x Set of 4 Pump Housing Bolts (90119-08M15-00)
- 1 x Pump Housing Cover (63D-44312-00-00)
- 1 x O-Ring (93210-59MG7-00)
- 1 x Water Seal (663-44366-00-00)
- 4 x Bolt Washers (90209-08M02-00)
- 1 x Water Pump Housing (66T-44311-00-00)
Installation Notes
- Disconnect the battery and remove the ignition key before beginning service.
- Place the outboard in a secure service position and follow the manufacturer's service procedure for lower-unit removal.
- Remove the lower unit and access the water pump assembly.
- Remove the old pump housing, impeller, gasket, plate, key, insert cup, seals and related hardware.
- Clean all mating surfaces and inspect the driveshaft, water tube and pump base before assembly.
- Install the new gasket, plate, impeller key and impeller. Rotate the driveshaft in the normal direction while seating the impeller vanes in the housing.
- Install the insert cup, water seal, O-ring, cover, housing and washers using the supplied hardware.
- Tighten fasteners to the torque values specified in the applicable Yamaha service manual.
- Reinstall the lower unit, ensuring correct alignment of the driveshaft and water tube.
- Run the engine using the appropriate water-supply method and confirm a strong cooling-water tell-tale stream before normal operation.
Maintenance & Troubleshooting FAQ
What are common signs of a failing water pump impeller?
Common signs include a weak or intermittent tell-tale stream, an overheating warning, rising engine temperature, or steam from the exhaust. Stop operation and investigate promptly to help prevent engine damage.
How often should the water pump be serviced?
Inspect the impeller during routine maintenance and replace it when it shows cracking, hardening, deformation or wear. Service intervals should follow the maintenance schedule for your specific Yamaha outboard and the conditions in which it operates.
Does this kit include the water pump housing?
Yes. This listing is for the kit configuration with the water pump housing. The package also includes the impeller, plate, gasket, key, insert cup, cover, seals, O-ring, washers and bolts listed in the box contents.
Will this kit fit every Yamaha 25–40 HP outboard?
No. The documented applications are select Yamaha T25 models from 2001–2004, F30 models from 2001–2004, and F40 models from 2000–2004. Verify the full model designation, year and original pump reference before purchase.
Is this an OEM Yamaha part?
No. This is an aftermarket replacement kit. Yamaha reference numbers are provided only for identification and fitment comparison.
Do I need any additional installation supplies?
Have the applicable service manual, suitable marine grease and any required lower-unit lubricant available. Additional parts may be needed if inspection finds damage outside the water pump assembly.
Safety & Important Information
- Verify the exact Yamaha model, year and original water pump reference before ordering.
- Do not rely on horsepower alone to confirm fitment.
- Disconnect the battery and follow the manufacturer's service and torque procedures during installation.
- Professional installation is recommended if you are not familiar with lower-unit or water-pump service.
- This is an aftermarket replacement, not an OEM Yamaha component.
About Sea Sierra
- Marine Replacement Parts — Practical aftermarket components for routine outboard service and repair.
- Fitment-Focused Listings — Model, year and reference information is provided to help customers compare replacement parts.
- Service-Ready Kits — Convenient component kits for common marine maintenance tasks.
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