Water Pump Impeller Repair Kit – Fits Yamaha 8HP/9.9HP Outboards (Replaces 68T-W0078-00-00)
This is a complete water pump repair kit for Yamaha 4-stroke 8HP and 9.9HP outboard engines. The kit provides all components required for a full and reliable water pump rebuild, ensuring your engine maintains proper cooling performance.
This assembly is a direct replacement for Yamaha part numbers 68T-W0078-00-00, 68T-W0078-01-00, and 68T-W0078-02-00, as well as Sierra 18-3450 and Mallory 9-48613.
- Includes impeller, housing components, seals, and hardware for a comprehensive service.
- Features an impeller manufactured from high-quality rubber formulated to withstand extended saltwater immersion.
- Designed for direct OEM replacement with no modifications needed for installation.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
Brand |
Part Number |
Superseded By |
Yamaha |
68T-W0078-00-00 |
68T-W0078-01-00 |
Yamaha |
68T-W0078-01-00 |
68T-W0078-02-00 |
Yamaha |
68T-W0078-02-00 |
|
Sierra |
18-3450 |
|
Mallory |
9-48613 |
|
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 |
F6 |
6 |
4-Stroke |
Up to 06/2008 |
68T-W0078-00-00 |
Later models use 68T-W0078-02-00 |
Yamaha |
F8 |
8 |
4-Stroke |
Up to 06/2008 |
68T-W0078-00-00 |
Later models use 68T-W0078-02-00 |
Yamaha |
F9.9 |
9.9 |
4-Stroke |
Up to 06/2008 |
68T-W0078-00-00 |
Later models use 68T-W0078-02-00 |
Technical Specifications
Specification |
Value |
Product Type |
Water Pump Repair Kit |
Installation |
Direct OEM replacement |
Housing Material |
High quality rubber (impeller) |
Other Technical Attributes |
Impellers manufactured to withstand extended salt water immersion |
Package Contents
- 1 x Cartridge Insert (63V-44322-00-00)
- 1 x Water Seal Damper 2 (68T-44366-00-00)
- 1 x Impeller (68T-44352-00-00)
- 1 x Woodruff Key (664-44338-00-00)
- 1 x O-Ring (93210-44704-00)
- 1 x Cartridge Outer Plate (68T-44323-00-00)
- 4 x Bolts (97095-08045-00)
Installation Guide
- Disconnect the negative battery cable and remove the engine cover.
- Shift the outboard into neutral and remove the bolts securing the lower unit (gearcase).
- Carefully separate the lower unit from the upper casing, watching for the shift shaft and speedometer tube.
- Place the lower unit on a workbench and remove the bolts for the water pump housing.
- Slide the housing up and off the driveshaft to expose the impeller. Note the rotational direction of the old impeller vanes.
- Remove the old impeller, woodruff key, wear plate, and gaskets.
- Clean all mating surfaces thoroughly, removing any old gasket material or corrosion.
- Install the new gasket, wear plate, and woodruff key from the kit.
- Lightly lubricate the new impeller with marine grease and slide it onto the driveshaft, turning it in the direction of engine rotation to seat the vanes.
- Apply a thin layer of grease to the inside of the new pump housing and install it over the impeller.
- Secure the housing with the new bolts provided, tightening them to the manufacturer's torque specifications.
- Reassemble the lower unit to the engine, ensuring the driveshaft, shift shaft, and water tube align correctly before tightening bolts.
Troubleshooting & FAQ
Q: How do I confirm this fits my engine?
A: First, check your engine model, horsepower, and year against the "Compatible Engine Models" table above. This kit is specifically for Yamaha 4-stroke 6HP, 8HP, and 9.9HP models manufactured up to June 2008. It directly replaces OEM part number 68T-W0078-00-00 and its successors. Verifying your existing part number is the best way to guarantee fitment.
Q: What are the signs of a failing water pump impeller?
A: The most common signs are a weak or non-existent water stream from the engine's tell-tale outlet, frequent engine overheating alarms, or a melted water pump housing. During a visual inspection, a worn impeller will have cracked, brittle, or permanently curved vanes.
Q: How often should I replace the impeller?
A: As a crucial part of preventative maintenance, we recommend replacing your impeller every 1 to 2 years or every 100-200 hours of operation. Service intervals should be shorter if you frequently operate in saltwater, silt, or sandy conditions.
Q: OEM vs. Aftermarket?
A: 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.
Q: How fast do you ship and how much does it cost?
A: 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.
Q: What is your warranty and return policy?
A: 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.