Water Pump Repair Kit Without Housing – Fits Yamaha F6 and F8 4-Stroke Outboards, 2001–2005 (Replaces 68T-W0078-00, Sierra 18-3450)
Water Pump Repair Kit Without Housing – Fits Yamaha F6 and F8 4-Stroke Outboards, 2001–2005 (Replaces 68T-W0078-00, Sierra 18-3450) is backordered and will ship as soon as it is back in stock.
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Water Pump Repair Kit Without Housing – Fits Yamaha F6 and F8 4-Str...
Water Pump Repair Kit Without Housing – Fits Yamaha F6 and F8 4-Stroke Outboards, 2001–2005 (Replaces 68T-W0078-00, Sierra 18-3450) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Repair Kit services the lower-unit water pump on selected Yamaha F6 and F8 4-stroke outboard engines from 2001 through 2005. It replaces worn internal water-pump components to help restore proper cooling-water circulation and reduce the risk of overheating caused by a damaged or deteriorated impeller.
This is the version supplied without the outer water-pump housing. The existing housing must be inspected and reused if it is serviceable. The kit is listed as a replacement for Yamaha OEM part number 68T-W0078-00 and Sierra Marine part number 18-3450.
- Installs in the lower-unit water-pump assembly.
- Includes the internal service components identified below.
- Does not include the outer water-pump housing.
- Confirm the exact engine model, year, and existing part before ordering.
Part Number Matrix
These are the documented manufacturer and aftermarket references associated with this water-pump kit.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 68T-W0078-00 | OEM reference listed for the water-pump kit. |
| Yamaha | 68T-W0078-00-00 | OEM reference listed for the version without housing. |
| Sierra | 18-3450 | Aftermarket water pump kit without housing. |
Engine & Model Compatibility
The documented application is limited to the Yamaha engine family and year range shown below. Model suffixes, shaft lengths, and serial-number ranges can affect fitment, so compare the original water-pump parts before installation.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | F6 | 6 | 4-Stroke | 2001–2005 | 68T-W0078-00 |
| Yamaha | F8 | 8 | 4-Stroke | 2001–2005 | 68T-W0078-00 |
Technical Specs
- Product Type
- Water pump repair kit without housing
- Installation
- Lower-unit water-pump service
- Housing
- Not included; reuse the original housing only if it is undamaged and within service limits
- Application
- Yamaha F6 and F8 4-stroke outboards, 2001–2005 application range
What’s in the Box
- 1 x Water pump impeller
- 1 x Wear plate
- 1 x Water-damper seal
- 1 x Impeller key
- 1 x Insert cup
- 1 x O-ring
- 4 x Water-pump bolts
Not included: outer water-pump housing.
Installation Notes
- Disconnect the battery and remove the spark-plug leads before beginning work.
- Place a drain pan under the lower unit and drain the gearcase lubricant according to the engine service procedure.
- Remove the gearcase from the outboard and expose the water-pump assembly.
- Remove the pump cover, old impeller, key, wear plate, seal, insert cup, O-ring, and bolts.
- Inspect the reused pump housing for scoring, distortion, corrosion, or excessive wear. Replace the housing if it is not serviceable.
- Clean the mating surfaces and install the new components in the correct order.
- Make sure the impeller key is fully seated and the impeller is installed in the correct orientation.
- Reassemble the water pump and lower unit according to the engine manufacturer’s service procedure, then refill the gearcase with the specified lubricant.
- Run the engine in water or with an appropriate flushing device and confirm a steady cooling-water discharge before returning it to service.
Troubleshooting & FAQ
How do I confirm this kit fits my Yamaha engine?
Check the complete engine model and year against the compatibility table, then compare the removed water-pump components and OEM reference. This documented application is for Yamaha F6 and F8 4-stroke outboards from 2001–2005. Do not rely on horsepower alone.
Does this kit include the outer pump housing?
No. This is the version without housing. The original housing must be reused only after confirming that its sealing surfaces and internal bore are serviceable.
What components are replaced?
The kit includes the impeller and the listed internal service parts: wear plate, water-damper seal, impeller key, insert cup, O-ring, and water-pump bolts.
What are the signs of a worn water-pump impeller?
Possible symptoms include weak or intermittent cooling-water discharge, overheating at idle or low speed, and an overheat warning. Inspect the complete water-pump assembly before replacing parts.
How often should the impeller be replaced?
Replacement intervals depend on the engine manufacturer’s maintenance schedule and operating conditions. Saltwater, sand, silt, and long periods of storage can accelerate wear. Inspect the impeller during scheduled service and replace it when damaged, hardened, cracked, or excessively worn.
Is this an OEM component?
This listing is for an aftermarket replacement kit. Yamaha and Sierra numbers are provided as reference numbers for identification and compatibility.
Safety & Important Info
- Verify the engine model, year, part references, and component dimensions before purchase.
- Do not install a damaged or scored water-pump housing with new internal parts.
- Follow the engine manufacturer’s service manual for torque values, sealants, lubricant, and testing procedures.
- Professional installation is recommended if you are not familiar with outboard lower-unit service.
About Sea Sierra
- Pro-Grade Standards — We supply marine replacement parts selected for dependable service in real-world operating conditions.
- Fast Global Fulfillment — Standard delivery options are available to most regions; delivery times vary by destination.
- Manufacturer-Direct Value — Practical replacement parts with clear application and component information.
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