Water Pump Wear Plate for Select Yamaha Outboards – Replaces 663-44323-00

Product Details

This Water Pump Wear Plate is a single replacement component for the water pump assembly used on select Yamaha outboard engines. It is identified as a replacement for Yamaha OEM part number 663-44323-00. The wear plate provides the pump surface beneath the impeller and should be inspected whenever the water pump is serviced.

Fitment is model-specific. Confirm the complete engine model, year or serial number where applicable, and the original part number before ordering. The compatibility information below is based on catalog references for the 663-44323-00 water-pump application and should not be treated as universal fitment for every Yamaha engine in the same horsepower class.

• Replacement water pump wear plate for select Yamaha outboards
• Designed for use with the corresponding water pump and impeller assembly
• Suitable for replacement during water pump inspection, repair, or rebuild
• Sold as one wear plate only; other water pump components are not included

Part Number Information

Use the following manufacturer reference to compare the replacement with the part removed from your engine.

Engine & Model Compatibility

The catalog references below associate Yamaha OEM reference 663-44323-00 with the following model groups. Because model designations can vary by market and production period, verify the engine identification and original part before installation.

Technical Specifications

Component

Water pump wear plate

Application

Selected Yamaha outboard water pump assemblies

Yamaha OEM reference

663-44323-00

Product type

Single replacement component, not a kit

Horsepower

See the model-specific compatibility table

What's in the Box

• 1× Water pump wear plate

The impeller, pump housing, gaskets, key, seals, and other water pump components are not included unless separately stated in the order details.

Installation Notes

1. Identify the engine model and confirm the replacement part against the original wear plate before disassembly.
2. Disconnect the battery and remove the lower unit according to the engine manufacturer's service procedure.
3. Remove the water pump cover or housing, impeller, and old wear plate.
4. Clean the mating surfaces and remove gasket material, corrosion, and debris without damaging the pump base.
5. Install the replacement wear plate in the same position and orientation as the original component.
6. Inspect the impeller, pump housing, key, seals, and gaskets. Replace worn or damaged parts as required.
7. Reassemble the water pump and tighten fasteners to the manufacturer's specified torque.
8. Reinstall the lower unit and reconnect the shift linkage and other fittings according to the service manual.
9. Run the engine in an appropriate test tank or on the water and verify a steady cooling-water discharge before normal operation.

Troubleshooting & FAQ

What does the wear plate do?

The wear plate forms the working surface beneath the water-pump impeller. Excessive grooves, scoring, warping, or corrosion can reduce pump efficiency and affect cooling-water flow.

How do I confirm fitment?

Compare the original part number, wear-plate shape, pump assembly, complete engine model, and serial information with the compatibility information above. Horsepower alone is not sufficient to confirm fitment.

Does this listing include an impeller or gasket?

No. This listing is for one wear plate only. The impeller, gasket set, pump housing, key, and other components are sold separately unless specifically included in the order details.

Should the wear plate be replaced with the impeller?

Inspect the wear plate whenever the impeller is replaced or the water pump is opened. Replace it if it is grooved, cracked, warped, corroded, or otherwise worn beyond the manufacturer's service limits.

Can the old gasket be reused?

Reuse is not recommended for removed water-pump gaskets. Follow the engine service manual and install the correct new gasket or seal whenever required.

Is this an OEM part?

This is an aftermarket replacement component. Yamaha OEM reference 663-44323-00 is provided for identification and fitment comparison; the replacement is not represented as a Yamaha-branded OEM part.

Safety & Important Information

• Verify the original part number and complete engine identification before ordering.
• Do not rely on horsepower alone because the same horsepower rating can cover different pump assemblies.
• Use the manufacturer's service manual for removal, installation, torque, sealing, and testing procedures.
• Stop operation immediately if the engine overheats or the cooling-water discharge is weak or absent.
• Professional installation is recommended when lower-unit service or shift-linkage adjustment is required.

About Sea Sierra

• Replacement marine components selected for common service and repair applications.
• Clear part-number and fitment references to help match the replacement with the original component.
• Support for routine water-pump maintenance and lower-unit service needs.