Water Pump Impeller – Fits Mercury Marine (Replaces 809866T, 47-809866T)

$19.57 $31.00

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Water Pump Impeller – Fits Mercury Marine (Replaces 809866T, 47-809866T) is backordered and will ship as soon as it is back in stock.

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If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This replacement Water Pump Impeller is designed for Mercury Marine Hino Diesel EH700N and EH700TI engines from 1987 and later. Engineered with a durable neoprene body and a brass hub, it ensures reliable performance in raw water cooling systems.

It serves as a direct interchange for several OEM and aftermarket part numbers, including Mercury Marine 809866T, Yanmar 119593-42202, and Jabsco 31130-0061.

Constructed from high-quality neoprene for flexibility and longevity.
Features a 12-point spline drive for precise shaft engagement.
Includes one impeller, ready for installation.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number	Notes
Mercury Marine	809866T / 47-809866T	Current active part number.
Mercury Marine	809866 / 47-809866	Superseded by 809866T.
Mercury Marine	831311350 / 47-831311350	Superseded by 809866.
Jabsco	31130-0061 / 31130-0061-P
Yanmar	119593-42200 / 119593-42201 / 119593-42202
EMP	47-47265
CEF	500161
Kashiyama	SP-130

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Designed for specific Hino diesel engines utilized by Mercury Marine.

Brand	Model	Years	OEM Part No.	Notes
Mercury Marine	Hino Diesel EH700N	1987 and later	809866T	Supersedes 809866 and 831311350
Mercury Marine	Hino Diesel EH700TI	1987 and later	809866T	Supersedes 809866 and 831311350

Technical Specs

Product Type: Water Pump Impeller
Material: Neoprene
Drive Type: 12-point Spline
Number of Blades: 10
Hub Material: Brass
Dimensions: 2-19/32" (65.88 mm) diameter × 2-11/16" (68.26 mm) depth
Shaft Diameter: 5/8" (15.8 mm)
Weight: 0.9 lbs (0.41 kg)
Silhouette Letter: Q
Liquid Type: Water

What’s in the Box

1 × Water Pump Impeller (809866T)

Installation Notes

Before starting, disconnect the battery and close the water inlet seacock.
Locate the raw water pump and remove the screws from the cover plate.
Take note of the blade direction of the old impeller before removing it.
Use needle-nose pliers or a dedicated impeller puller to extract the old impeller.
Clean the pump housing interior and inspect for wear or damage.
Lightly lubricate the new impeller and housing with marine-safe glycerine or a soap solution (avoid petroleum grease).
Install the new impeller by pushing inward while twisting to correctly bend the blades.
Replace the cover plate with a new gasket and tighten the screws securely.
After reassembly, open the seacock, start the engine, and immediately check for leaks.

Troubleshooting & FAQ

How do I know if this impeller fits my engine?

This impeller is designed for the Mercury Marine engine models listed above. The most reliable way to confirm fitment is to match your existing part number to one of the equivalents in the Part Number Matrix. Also, verify the technical specifications (especially dimensions and drive type) against your old part.

What are the signs of a failing impeller?

Common symptoms include the engine overheating at idle or low speeds, a noticeable reduction in water flow from the exhaust outlet, or visible cracks, stiffness, or missing blades on the impeller itself during inspection.

How often should a water pump impeller be replaced?

As a preventative maintenance item, it's recommended to replace the impeller every one to two years, or per the schedule in your engine's service manual. If your boat operates in silty or sandy water, more frequent inspections are advised.

Is there a correct orientation for installation?

Yes. The impeller blades must be bent in the correct rotational direction of the pump housing. When removing the old impeller, note which way its blades are curved. Install the new one by twisting it gently in the same direction to ensure proper water flow.

What is the advantage of a neoprene impeller?

Neoprene is a robust, flexible synthetic rubber that offers excellent durability and performance in marine raw water cooling applications. It is resilient against wear from small debris and maintains its flexibility over a wide temperature range.

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.

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