Water Pump Housing – Fits Yamaha 55HP 2-Stroke (Replaces 663-44311-02-00)
Water Pump Housing – Fits Yamaha 55HP 2-Stroke (Replaces 663-44311-02-00) 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 aftermarket Water Pump Housing is a direct-fit replacement for specified Yamaha 2-Stroke outboard motors. It is designed for 55HP C55 models manufactured between 1990 and 1994.
It serves as a direct replacement for Yamaha OEM part number 663-44311-02-00 and is also included in the Sierra 18-3425 full water pump repair kit.
- Engineered for a direct fit, facilitating straightforward installation.
- Mounts directly to the lower unit as part of the cooling system.
- Features a weep hole to prevent coolant from leaking into the bearing assembly.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 663-44311-02-00 | |
| Sierra | 18-3425 | Included with full pump kit |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | C55 | 55 | 2-Stroke | 1990–1991 | 663-44311-02-00 |
| Yamaha | C55 | 55 | 2-Stroke | 1992–1994 | 663-44311-02-00 |
Technical Specs
- Product Type
- Water Pump Housing
- Installation
- Direct fit replacement
- Connection
- Direct mount to lower unit
- Dimensions
- 11.0" L x 9.5" W x 6.5" H
- Fitting Type
- Lower unit mount
- Other Technical Attributes
- Features weep hole to prevent coolant leakage into bearing assembly
What’s in the Box
- 1 x Water Pump Housing (Replaces 663-44311-02-00)
Installation Notes
- Disconnect the battery and remove the negative terminal.
- Drain the gearcase lubricant from the lower unit.
- Remove the propeller assembly.
- Unbolt and carefully lower the gearcase from the outboard's midsection.
- Locate the water pump assembly and remove the bolts securing the housing.
- Lift off the old housing. Remove the impeller, wear plate, and any gaskets.
- Thoroughly clean all mating surfaces, removing any old gasket material or sealant.
- Install the new housing and components in the reverse order of removal.
- Ensure the impeller key is correctly seated and the driveshaft is aligned.
- Torque all bolts to the manufacturer's recommended specifications.
- Reattach the gearcase, reinstall the propeller, and refill with fresh gear lube.
- Start the engine using a water supply (flushing muffs) and check for proper water flow from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if this housing fits my engine?
Refer to the compatibility table. This housing is confirmed to fit Yamaha C55 2-Stroke models from 1990–1994. Always verify your engine's model, year, and original part number before ordering.
What are the signs of a failing water pump housing?
Common symptoms include the engine overheating at idle or low speeds, a weak or intermittent water stream from the "tell-tale" outlet, or visible cracks, warping, or melting on the existing housing.
How often should the water pump assembly be serviced?
For preventative maintenance, it's recommended to inspect the water pump and replace the impeller annually or every 100 hours of use, whichever comes first. The housing should be replaced whenever it shows signs of wear, abrasion, or heat damage.
Is this a complete water pump kit?
No, this listing is for the water pump housing only. For a complete rebuild kit that includes this housing along with the impeller, gaskets, and plates, reference Sierra part number 18-3425.
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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