Water Pump Impeller – Fits Honda 8–20 HP Outboards (Replaces 19210-ZW9-A31, 19210-ZW9-A32)

Water Pump Impeller – Fits Honda 8–20 HP Outboards (Replaces 19210-ZW9-A31, 19210-ZW9-A32)

This water pump impeller is designed for Honda Marine 4-stroke outboard engines, including 8 HP, 9.9 HP, 15 HP, and 20 HP models from the year 2000 and newer. It also serves as a compatible replacement for select Mercury/MerCruiser engines that use the same impeller design.

It is a direct replacement for several OEM and aftermarket part numbers, including Sierra 18-32455, GLM 91015, CEF 500348, Rec 324351, GLM 12510, Mercury/MerCruiser 8M0204677, and Johnson/Evinrude 0508389.

• Installation Method: Installs as a direct OEM replacement.
• Material: Constructed from high-quality neoprene rubber for durability.
• Design: Features a 9-blade design with an internal spline fitting for efficient water flow.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson Serial Number Guide.

Honda Outboards

Mercury/MerCruiser

Johnson/Evinrude

Technical Specifications

Package Contents

• 1 x Water Pump Impeller (Replaces Honda 19210-ZW9-A31 / 19210-ZW9-A32)

Explosion Diagram

Installation Guide

1. Disconnect the negative battery cable and ensure the engine is off.
2. Place a drain pan under the lower unit and remove the gearcase drain/fill screws to drain the gear lube.
3. Remove the bolts connecting the lower unit (gearcase) to the upper leg of the outboard.
4. Carefully lower the gearcase to expose the water pump assembly on top of the driveshaft.
5. Remove the bolts on the water pump housing to access the impeller. Note the orientation of the old impeller's blades.
6. Slide the old impeller off the driveshaft. Clean the housing and wear plate of any debris or corrosion.
7. Lightly lubricate the interior of the new impeller and the housing with marine grease.
8. Install the new impeller onto the driveshaft, rotating the shaft clockwise to bend the blades in the correct direction.
9. Reassemble the water pump housing and torque the bolts to the manufacturer's specification.
10. Reinstall the lower unit, ensuring the driveshaft and water tube align correctly.
11. Refill the gearcase with fresh lubricant and test the engine in water to confirm proper cooling and water flow.

Troubleshooting & FAQ

How do I confirm this fits my Honda engine?

Verify your engine's model, horsepower, and year against the compatibility table. For 8 HP and 9.9 HP models, this impeller specifically fits extra-long shaft (25") versions manufactured from 2000 onwards. For 15 HP and 20 HP models, it fits all shaft lengths from the same period.

What are the signs of a failing water pump impeller?

Common symptoms include the engine overheating at idle or low speeds, a weak or intermittent water stream from the tell-tale outlet, or a complete lack of water flow. A damaged impeller cannot effectively pump cooling water through the engine.

How often should I replace the impeller?

For preventative maintenance, it is recommended to inspect your impeller annually and replace it every 1 to 2 years or every 100-200 hours of operation, whichever comes first. Usage in saltwater or sandy/silty conditions may require more frequent replacement.

OEM vs. Aftermarket?

This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?

We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?

This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.