Impeller Kit – Fits Yamaha Outboard 4-Stroke F25, F30, F40 (Replaces Yamaha 6-Stroke 6BL-W0078-00)
Impeller Kit – Fits Yamaha Outboard 4-Stroke F25, F30, F40 (Replaces Yamaha 6-Stroke 6BL-W0078-00) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Impeller Kit – Fits Yamaha Outboard 4-Stroke F25, F30, F40 (Replace...
Product Details
This aftermarket Impeller Kit – Fits Yamaha Outboard 4-Stroke F25, F30, F40 provides all the necessary components for servicing the water pump on Yamaha F25, F30, and F40 series 4-stroke outboards from approximately 2001 to 2018. It is designed as a direct replacement for OEM part number 6BL-W0078-00, ensuring proper cooling system function.
- Installs in the outboard's lower unit.
- Engineered to meet or exceed original equipment specifications.
- Kit includes all essential seals, gaskets, and hardware for a complete rebuild.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6BL-W0078-00 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is compatible with select 4-stroke outboard models from Yamaha.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | F25 (F25D, F25G, F25L) | 25 | 4-Stroke | 2005–2018 | 6BL-W0078-00 |
| Yamaha | F30 (F30B) | 30 | 4-Stroke | 2001–2009 | 6BL-W0078-00 |
| Yamaha | F40 (F40B, F40F, F40H) | 40 | 4-Stroke | 2001–2018 | 6BL-W0078-00 |
Technical Specs
- Product Type
- Impeller Kit
- Installation
- Outboard Lower Unit
- Dimensions
- 10.0" L x 11.0" W x 7.0" H
Installation Notes
- Disconnect the battery and shift the outboard into the neutral position.
- Drain the gearcase oil from the lower unit.
- Remove the bolts securing the lower unit to the midsection and carefully lower it.
- Locate and unbolt the water pump housing, noting the orientation of the bolts.
- Lift the housing to expose the impeller. Remove the old impeller, key, gaskets, and wear plate.
- Clean all mating surfaces thoroughly, removing any old gasket material or corrosion.
- Install the new gaskets, wear plate, and insert cartridge. Lightly grease the interior of the new housing.
- Slide the new woodruff key onto the driveshaft and align the new impeller, rotating it clockwise while pushing down to seat it.
- Install the new water pump housing and tighten the bolts to the manufacturer's specified torque.
- Re-install the lower unit, ensuring the driveshaft, shift shaft, and water tube are correctly aligned.
- Refill the gearcase with fresh oil and reconnect the battery.
- Test run the engine with a water supply, checking for proper water output from the tell-tale port.
Troubleshooting & FAQ
How do I know if my impeller needs replacing?
Common signs of a failed or worn impeller include a weak or non-existent water stream from the "tell-tale" port, engine overheating alarms, and in severe cases, steam from the exhaust. It is recommended to replace the impeller as part of regular preventative maintenance every 1-2 years, regardless of visible signs.
Will this fit my specific F25G model year?
This kit is listed for F25 models, including the F25G, from 2005 through 2018. However, always verify by comparing the OEM part number (6BL-W0078-00) against your engine's service manual or parts diagram for that specific year and serial number.
Is this kit difficult to install?
Installation requires dropping the lower unit, which can be mechanically intensive. While it can be done by a knowledgeable DIYer with the correct tools, we recommend professional installation to ensure correct assembly, torque specifications, and sealing.
What parts are most critical to inspect during installation?
Besides replacing the impeller itself, carefully inspect the water pump housing and the metal wear plate underneath the impeller. If either surface is scored, grooved, or heavily corroded, it should be replaced to ensure the new impeller creates a proper seal and pumps efficiently.
What is the main difference between this and the OEM kit?
Our aftermarket kit is engineered to meet or exceed OEM specifications for fit, material, and performance. The primary difference is the price point and branding. We provide a high-quality, reliable alternative to the original manufacturer's part.
Do I need any special sealant for the gaskets?
Generally, the included gaskets are designed to be installed dry. However, a very light application of a marine-grade gasket sealing compound can sometimes help hold gaskets in place during assembly. Avoid using heavy sealants like silicone RTV, as they can squeeze out and clog water passages.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
Payment & Security
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