Water Pump Impeller Kit – Fits Mercury/Tohatsu/Nissan 25-30 HP 4-Stroke (Replaces 853792A07)
Water Pump Impeller Kit – Fits Mercury/Tohatsu/Nissan 25-30 HP 4-Stroke (Replaces 853792A07) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Water Pump Impeller Kit – Fits Mercury/Tohatsu/Nissan 25-30 HP 4-St...
Water Pump Impeller Kit – Fits Mercury/Tohatsu/Nissan 25-30 HP 4-Stroke (Replaces 853792A07) is backordered and will ship as soon as it is back in stock.
Product Details
This comprehensive Water Pump Impeller Kit – Fits Mercury/Tohatsu/Nissan 25-30 HP 4-Stroke (Replaces 853792A07) is designed for select Mercury, Tohatsu, and Nissan 25-30 HP 4-stroke outboard motors. It provides a reliable solution for maintaining your engine's cooling system, specifically fitting Mercury Marine models from serial number 0R051710 and up (including EFI) and a wide range of Tohatsu/Nissan 25-30 HP 4-stroke models.
This kit serves as a direct replacement for multiple OEM part numbers, including Mercury 853792A07, 853792A1, 853792T01, and Tohatsu/Nissan 361873220, ensuring a precise fit and function.
- Engineered for direct replacement and easy installation.
- Restores cooling system circulation to prevent overheating.
- Includes all essential components: impeller, gaskets, and hardware.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury | 853792A07 | Primary Replacement |
| Mercury | 853792A1 | Superseded Part |
| Mercury | 853792T01 | Superseded Part |
| Tohatsu / Nissan | 361873220 | Primary Replacement |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury Marine outboards, verify that your engine's serial number falls within the specified range (e.g., "0R106999 and above").
For Tohatsu and Nissan outboards, match your model number and manufacturing years from the list.
| Brand | Model | Rated HP | Stroke | Years / S/N | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 25 HP EFI | 25 | 4-Stroke | 0R106999 and above | 853792A07 | Gear Housing |
| Mercury | 25 HP EFI JET | 25 | 4-Stroke | 0R165086 and above | 853792A07 | Gear Housing |
| Mercury | 25 HP Sea Pro | 25 | 4-Stroke | 0R051710 and above | 853792A07 | Gear Housing (Driveshaft) |
| Mercury | 30 HP EFI | 30 | 4-Stroke | 0R106999 and above | 853792A07 | Gear Housing |
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Tohatsu | M25C3 | 25 | 4-Stroke | 2002–2005 | 361873220 | |
| Tohatsu | M30A4 | 30 | 4-Stroke | 2002–2003 | 361873220 | |
| Nissan | NS25C3 | 25 | 4-Stroke | 2002–2005 | 361873220 | |
| Nissan | NS30A4 | 30 | 4-Stroke | 2002–2003 | 361873220 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Direct replacement
- Primary Function
- For outboard cooling system circulation
What’s in the Box
- 1 x Water Pump Impeller
- 4 x Mounting Bolts
- 1 x Metal Gasket with holes
- 1 x Dark Grey Gasket
- 1 x Metal Retainer with slot
Installation Notes
- Disconnect the battery and ensure the engine is off and cool.
- Drain the lower unit gear lube.
- Remove the propeller and lower unit (gearcase) bolts.
- Carefully detach the lower unit from the driveshaft housing.
- Unbolt and remove the old water pump housing.
- Remove the old impeller, gaskets, and key.
- Clean all mating surfaces thoroughly, removing any old gasket residue.
- Install the new gaskets, plate, and impeller from the kit. Ensure the impeller key is correctly seated.
- Lubricate the inside of the housing and reinstall it, torquing bolts to manufacturer specifications.
- Reattach the lower unit, ensuring the driveshaft, shift shaft, and water tube are aligned.
- Refill the gear lube and test the engine cooling system using a flush-muff on land.
Troubleshooting & FAQ
How can I tell if this kit fits my specific Mercury outboard?
The most reliable method is to check your engine's serial number. This kit is compatible with Mercury 25-30 HP 4-stroke models with a serial number of 0R051710 and higher. You can find the serial number on a tag on the engine's transom bracket.
What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, and in some cases, a rattling or grinding noise from the lower unit. It is recommended to replace the impeller as part of regular maintenance, typically every 1-2 years or 100-200 hours of use.
Is this a complete kit for the job?
Yes, this kit includes the core components needed for a standard water pump service: the impeller, gaskets, plate, and new mounting bolts. You will only need standard mechanic's tools and a new supply of gear lube.
My Tohatsu engine isn't listed, will it fit?
This kit is specifically designed for the Tohatsu models M25C3 (2002–2005) and M30A4 (2002–2003). If your model or year is not listed, we cannot guarantee compatibility. Please cross-reference your OEM part number (361873220) to be certain.
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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