Water Pump Wear Plate – Fits Yamaha Outboard Motors (Replaces 663-44323-00-00)
Water Pump Wear Plate – Fits Yamaha Outboard Motors (Replaces 663-44323-00-00) 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
Product Details
This replacement Water Pump Wear Plate – Fits Yamaha Outboard Motors (Replaces 663-44323-00-00) is designed for a precise fit on Yamaha outboard motors that use this specific cartridge outer plate design in the lower unit's water pump assembly. It serves as a crucial surface for the impeller, ensuring efficient cooling performance.
This part directly interchanges with Yamaha 663-44323-00-00 and SEI MARINE PRODUCTS 663-44323-00.
- Installs as a primary component of the outboard's lower unit water pump.
- Engineered as a direct factory replacement part for specified Yamaha outboard lower units.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 663-44323-00-00 |
| SEI MARINE PRODUCTS | 663-44323-00 |
Technical Specs
- Product Type
- Water Pump Wear Plate / Cartridge Outer Plate
- Installation
- Component of outboard lower unit water pump assembly
- Dimensions
- Height: 6.0 in; Width: 7.13 in; Length: 0.13 in;
- Other Technical Attributes
- Factory replacement part for Yamaha outboard lower units
What’s in the Box
- 1 x Water Pump Wear Plate / Cartridge Outer Plate (663-44323-00-00)
Installation Notes
- Disconnect the battery and remove the engine cowling.
- Drain the lower unit's gear lube into an approved container.
- Remove the bolts securing the lower unit (gearcase) and carefully detach it from the outboard's midsection.
- Unbolt and remove the water pump housing to access the impeller and wear plate.
- Note the orientation of all components, then remove the old wear plate.
- Thoroughly clean the mounting surface, removing any old gasket material or debris.
- Install the new wear plate, ensuring it is correctly seated.
- Reassemble the water pump, preferably with a new impeller and gaskets.
- Reinstall the lower unit, ensuring the driveshaft and water tube are properly aligned.
- Refill the gearcase with the manufacturer-specified lubricant.
- Reconnect the battery, start the engine in water, and verify a strong, steady stream from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if this wear plate fits my Yamaha outboard?
This plate is a direct replacement for OEM part number 663-44323-00-00. The most reliable way to ensure fitment is to check the part number listed in your engine's service manual. You should also visually compare our product images against your old part before ordering.
What are the signs of a failing water pump wear plate?
Common symptoms include the engine overheating, especially at low speeds or idle, and a weak or intermittent water stream from the "tell-tale" outlet. Upon inspection, a worn plate will show visible grooves, scoring, or warping where the impeller makes contact.
Should I replace any other parts at the same time?
Yes. For a complete and reliable repair, it is highly recommended to install a full water pump rebuild kit, which typically includes a new impeller, gaskets, O-rings, and seals, along with the wear plate.
Can I reuse my old gaskets?
No. Gaskets create critical seals within the water pump assembly. Old, compressed gaskets are a common source of leaks and pressure loss. Always use new gaskets during reassembly to ensure proper function and prevent cooling system failure.
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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