Water Pump Impeller Kit with Housing for Yamaha 150–300 HP Outboards – 2-Stroke and 4-Stroke

Product Details

This water pump impeller kit with housing is designed for servicing the lower-unit cooling system on selected Yamaha 150–300 HP outboards. The kit combines the pump housing components, impeller, gaskets, O-rings, dowel pins, fasteners, and impeller key needed for the water-pump service described below.

The listed cross-reference numbers include Yamaha 61A-W0078-A2-00, 61A-W0078-A3-00, and 61A-W0078-A4-00, together with aftermarket references Sierra 18-3396 and Mallory 9-48618. Cross-reference numbers are provided for identification; verify the exact engine model, year, and original component before ordering.

• Installation location: Lower unit or gearcase water pump.
• Materials: Nylon PA66 housing, neoprene-rubber impeller and O-rings, and stainless-steel hardware.
• Kit format: Includes the housing components and service parts listed in the package contents section.
• Application: Selected Yamaha 2-stroke and 4-stroke outboards; model, year, and engine configuration must be checked individually.

Part Number Matrix

Use the following numbers as cross-reference information when comparing the original water-pump assembly.

Engine and Model Compatibility

The following model, horsepower, stroke, and year combinations are the listed application data for this kit. Yamaha model families can vary by shaft length, gearcase, serial range, and production year. Confirm the complete model designation and compare the original pump components before installation.

Technical Specifications

Product type

Water pump impeller kit with housing

Installation

Lower unit / gearcase water pump

Housing material

Nylon PA66 plastic

Housing color

Black

Component materials

Stainless-steel hardware and neoprene-rubber impeller and O-rings

Package weight

Approximately 0.45 kg (16 oz)

Warranty

6 months

Listed application

Selected Yamaha 150–300 HP 2-stroke and 4-stroke outboards

What's in the Box

• 1 × Water pump impeller: 6E5-44352-01-00
• 1 × Cartridge insert: 61A-44322-02-00
• 1 × Cartridge outer plate: 6G5-44323-01-00
• 1 × Water pump gasket: 6E5-44315-A0-00
• 2 × O-rings: 93210-86M38-00 and 93210-37M67-00
• 2 × Dowel pins: 93606-12019-00
• 4 × Bolts with washers: 90119-08M14-00
• 1 × Impeller key / Woodruff key: 90280-04M05-00

Installation Notes

1. Disconnect the battery and remove the engine cowling. Drain the gearcase oil into a suitable container.
2. Unbolt and carefully lower the gearcase from the outboard midsection, disconnecting the speedometer tube if fitted.
3. Locate and remove the water-pump housing fasteners. Slide the housing up and off the driveshaft.
4. Remove the old impeller, wear-plate components, gaskets, O-rings, and key. Clean all mating surfaces thoroughly.
5. Install the new key, gasket, and plate components. Lightly lubricate the impeller and install it on the driveshaft while turning it in the correct direction for the engine.
6. Install the housing, insert, gaskets, and O-rings. Use marine-grade grease on the fastener threads and tighten all fasteners to the manufacturer's specified torque.
7. Reinstall the lower unit, making sure the driveshaft, shift shaft, and water tube are correctly aligned. Refill the gearcase with the appropriate lubricant.
8. Run the engine in water or with an appropriate flushing setup and verify a steady telltale stream before normal operation.

Troubleshooting and FAQ

Safety and Important Information

• Confirm the engine model, year, stroke, and gearcase configuration before ordering.
• Compare the supplied components with the original water-pump assembly before installation.
• This is an aftermarket replacement, not an OEM component.
• Follow the engine manufacturer's service procedures and torque specifications.
• Professional installation is recommended if you are not experienced with outboard lower-unit service.

About Sea Sierra

• Marine replacement parts: Components are selected for common service and repair applications.
• Application-focused listings: Product information is provided to help customers compare model, year, and part-number requirements.
• Customer support: Contact support with your engine model and original-part information if you need help confirming an application.