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) 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).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Impeller – Fits Honda 8–20 HP Outboards (Replaces 19210-...
Product Details
This aftermarket Water Pump Impeller – Fits Honda 8–20 HP Outboards is a direct replacement part engineered for reliability in Honda Marine 4-stroke engines, including 8 HP, 9.9 HP, 15 HP, and 20 HP models from 2000 and newer. It is also designed to be compatible with select Mercury/MerCruiser engines that utilize the same impeller specifications.
It serves as a direct interchange for several part numbers, including Sierra 18-32455, GLM 91015, CEF 500348, Mercury/MerCruiser 8M0204677, and Johnson/Evinrude 0508389.
- Engineered as an OEM-equivalent direct replacement for easy installation.
- Constructed from durable neoprene rubber to withstand the harsh marine environment.
- Features a 9-blade design with an internal spline fitting for optimal water flow.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Superseded By | Notes |
|---|---|---|---|
| Honda | 19210-ZW9-A31 | ||
| Honda | 19210-ZW9-A32 | ||
| Sierra | 18-32455 | ||
| GLM | 91015 | ||
| GLM | 12510 | ||
| CEF | 500348 | ||
| Mercury/MerCruiser | 8M0204677 | ||
| Mercury/MerCruiser | 324351 / 32435 / 32435B / 30605 | 8M0204677 | |
| Johnson/Evinrude | 0508389 | Cross-reference only |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Honda outboards, this impeller fits 2000 and newer models as specified. Pay close attention to shaft length requirements for 8 HP and 9.9 HP engines, as compatibility can vary.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Honda | BF8D | 8 | 4-Stroke | 2000+ | 19210-ZW9-A31/A32 | Extra long shaft (25") models |
| Honda | BFP8D | 8 | 4-Stroke | 2000+ | 19210-ZW9-A31/A32 | Extra long shaft (25") models |
| Honda | BF9.9D | 9.9 | 4-Stroke | 2000+ | 19210-ZW9-A31/A32 | Extra long shaft (25") models |
| Honda | BFP9.9D | 9.9 | 4-Stroke | 2000+ | 19210-ZW9-A31/A32 | Extra long shaft (25") models |
| Honda | BF15D/BFP15D | 15 | 4-Stroke | 2000+ | 19210-ZW9-A31/A32 | All shaft lengths |
| Honda | BF20D/BFP20D | 20 | 4-Stroke | 2000+ | 19210-ZW9-A31/A32 | All shaft lengths |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- OEM Direct Replacement
- Connection
- Internal Shaft Insert
- Housing Material
- Neoprene Rubber
- Housing Color
- Black
- Dimensions
- 45.6 mm OD × 16.2 mm ID × 14.8 mm H (1.80 in × 0.64 in × 0.58 in)
- Fitting Type
- Internal Spline
- Warranty
- Varies by manufacturer (typically 1 year)
- Other Technical Attributes
- 9 blade design with internal spline fitting
What’s in the Box
- 1 x Water Pump Impeller (Replaces 19210-ZW9-A31/19210-ZW9-A32)
Installation Notes
- Disconnect the negative battery cable to prevent accidental starting.
- Place the outboard motor in forward gear to simplify driveshaft removal.
- Remove the lower unit (gearcase) from the outboard's leg by unfastening the mounting bolts.
- Unbolt and remove the water pump housing to access the impeller. Note the orientation of the old impeller vanes.
- Slide the old impeller off the driveshaft. Clean the housing interior and inspect it for wear or damage.
- Apply a light coat of marine grease to the new impeller and housing interior.
- Install the new impeller by sliding it onto the driveshaft while turning the shaft clockwise to bend the vanes correctly.
- Reinstall the water pump housing, ensuring a proper seal. Reassemble the lower unit to the outboard and tighten all bolts to spec.
- Reconnect the battery, start the engine in water, and confirm a steady stream of water from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if my water pump impeller needs replacing?
Common signs of a failing impeller include a weak or non-existent water stream from the engine's tell-tale outlet, engine overheating alarms, or steam from the exhaust. During routine maintenance, inspect the impeller for cracked, brittle, or permanently bent vanes.
What is the recommended replacement interval for an impeller?
For optimal engine protection and reliability, most marine mechanics recommend replacing the water pump impeller every 1 to 2 years or every 100-200 hours of use, whichever occurs first. This interval can be shorter in saltwater or high-debris environments.
Will this fit my specific Honda outboard model?
This impeller is designed for specific Honda 8-20 HP models manufactured from 2000 onwards. It is critical to consult the "Engine & Model Compatibility" table and verify your exact model, year, and any notes regarding shaft length to ensure a correct fit.
My engine is overheating, but the tell-tale stream looks normal. Could it still be the impeller?
Yes. A partially failed or worn impeller might produce a visible water stream at idle or low RPMs but may not provide sufficient water volume to cool the engine under load. Also, check for blockages in the cooling water passages or a faulty thermostat.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9001 certified facility, batch-inspected for consistency and performance.
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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