Water Pump Impeller Repair Kit for Mercury/Mariner 25–30 HP and Tohatsu/Nissan 25–40 HP Outboards
Water Pump Impeller Repair Kit for Mercury/Mariner 25–30 HP and Tohatsu/Nissan 25–40 HP Outboards is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Water Pump Impeller Repair Kit for Mercury/Mariner 25–30 HP and Toh...
Water Pump Impeller Repair Kit for Mercury/Mariner 25–30 HP and Tohatsu/Nissan 25–40 HP Outboards is backordered and will ship as soon as it is back in stock.
Product Details
This water pump impeller repair kit is designed to service the raw-water pump on selected Mercury and Mariner 25–30 HP outboards, as well as various Tohatsu and Nissan 25–40 HP outboard models. It provides the principal service components needed to replace a worn impeller and renew the related pump sealing and wear components.
The kit is listed as a replacement for Mercury references 853792A1, 853792A07, and 853792T01, and for Tohatsu/Nissan references 361-87322-0, 361-87322-1, and 361-87322-2. The cited Mercury catalog relationship identifies 853792T01 as applicable to selected 20, 25, and 30 HP two-cylinder applications and lists 853792A1 as an interchange reference; always verify the complete model and serial-number range before ordering.
- Replacement water-pump service kit for selected marine outboards.
- Helps restore cooling-water-pump service components during routine maintenance.
- Includes the impeller, key, gaskets, insert, guide plate, and mounting hardware listed below.
- Aftermarket replacement; not an original equipment manufacturer component.
Part Number Matrix
Use these manufacturer and aftermarket references to compare the service part required for your engine. Part-number matching alone does not replace verification of the engine model, year, stroke, and serial-number range.
| Brand | Part Number |
|---|---|
| Mercury | 853792A1 |
| Mercury | 853792A07 |
| Mercury | 853792T01 |
| Tohatsu/Nissan | 361-87322-0 |
| Tohatsu/Nissan | 361-87322-1 |
| Tohatsu/Nissan | 361-87322-2 |
Engine & Model Compatibility
Confirm the complete model designation, year, stroke, and serial number against your engine before purchase. The Mercury/Mariner applications below are the listed fitment ranges for this kit.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 25 HP | 25 | 4-Stroke | 2006 and newer | 853792A1 / 853792A07 / 853792T01 | S/N 0N018456 and above |
| Mercury | 25 HP Sea Pro | 25 | 4-Stroke | 2006 and newer | 853792A1 / 853792A07 / 853792T01 | S/N 0R051710 and above |
| Mercury | 25 HP EFI | 25 | 4-Stroke | 2006 and newer | 853792A1 / 853792A07 / 853792T01 | S/N 0R106999 and above |
| Mercury | 25 HP EFI JET | 25 | 4-Stroke | 2006 and newer | 853792A1 / 853792A07 / 853792T01 | S/N 0R165086 and above |
| Mercury | 30 HP | 30 | 4-Stroke | 2006 and newer | 853792A1 / 853792A07 / 853792T01 | S/N 0N001875 and above |
| Mercury | 30 HP EFI | 30 | 4-Stroke | 2006 and newer | 853792A1 / 853792A07 / 853792T01 | S/N 0R106999 and above |
The kit is also listed for the following Tohatsu and Nissan 4-stroke model families. Because model-year and serial-number coverage may vary, compare the complete engine identification and the original pump components before installation.
| Brand | Model | Rated HP | Stroke | OEM Part No. |
|---|---|---|---|---|
| Tohatsu/Nissan | NS25C2, NS25C3, M25C2, M25C3, M25H, MX25H | 25 | 4-Stroke | 361-87322-0 / 361-87322-1 / 361-87322-2 |
| Tohatsu/Nissan | NS30A3, NS30A4, M30A3, M30A4, M30H, MX30H | 30 | 4-Stroke | 361-87322-0 / 361-87322-1 / 361-87322-2 |
| Tohatsu/Nissan | NS35C, M35C | 35 | 4-Stroke | 361-87322-0 / 361-87322-1 / 361-87322-2 |
| Tohatsu/Nissan | NS40C, NS40C2, M40C | 40 | 4-Stroke | 361-87322-0 / 361-87322-1 / 361-87322-2 |
Technical Specs
- Product Type
- Water pump impeller repair kit
- Application
- Raw-water pump service for selected Mercury, Mariner, Tohatsu, and Nissan outboards
- Installation
- Replacement installation using the original pump assembly and engine-specific service procedure
- Construction
- Aftermarket replacement components
What’s in the Box
- 1 × Water pump impeller; references 345-65021-0, 47-16154-1, and 161541
- 1 × Impeller key; reference 332-65022-0
- 1 × Gasket; reference 348-65029-1
- 1 × Gasket; reference 348-65018-0
- 1 × Housing insert; reference 348-65011-0
- 1 × Guide plate; reference 348-65025-0
- 4 × Bolts and washers; reference 910103-5652
Installation Notes
- Disconnect the negative battery cable and remove the upper engine cowling.
- Disconnect the shift linkage as required by the engine service procedure.
- Remove the fasteners securing the lower unit to the engine leg and carefully lower the gearcase.
- Remove the water-pump-housing fasteners and lift off the housing to expose the impeller.
- Remove the old impeller, key, gaskets, insert, and guide plate, noting their orientation and order.
- Clean the mating surfaces and inspect the pump housing, driveshaft keyway, and related components for corrosion, cracks, or distortion.
- Install the replacement gasket, guide plate, and housing insert in the correct order for your engine.
- Fit the key into the driveshaft keyway and install the impeller. Turn the driveshaft in the correct direction so the vanes fold naturally into the housing.
- Reinstall the pump housing and tighten the fasteners to the engine manufacturer’s specification.
- Reinstall the lower unit, reconnect the shift linkage, and test the engine in accordance with the manufacturer’s safety procedure. Confirm a strong tell-tale stream and normal operating temperature.
Installation should be performed by a qualified technician when the engine-specific service procedure or torque values are not available.
Troubleshooting & FAQ
How do I confirm fitment for my Mercury or Mariner engine?
Read the model and serial-number information from the engine identification label, usually located on the transom bracket or engine mounting area. Compare the complete model, year, stroke, horsepower, and serial range with the compatibility table. For the listed Mercury applications, the key ranges include S/N 0N018456 and newer for certain 25 HP models and S/N 0N001875 and newer for certain 30 HP applications.
What are the signs of a failing water-pump impeller?
Common signs include overheating at idle or low speed, a weak or intermittent tell-tale stream, reduced cooling-water flow, or brittle, cracked, or melted rubber pieces found during inspection.
How often should the impeller kit be replaced?
Inspect the impeller at the interval specified by your engine manufacturer and replace it when it shows wear, cracking, deformation, or damage. Frequent operation in saltwater, sand, silt, or contaminated water can shorten service life and may require more frequent inspection.
Is the impeller key included?
Yes. The kit includes one impeller key, along with the impeller, gaskets, housing insert, guide plate, and the listed bolts and washers.
My Tohatsu or Nissan model is listed, but the year is not shown. How can I confirm fitment?
Compare the complete model and serial number with the manufacturer’s parts information and compare the original impeller, key, gaskets, insert, and guide plate with the kit components. Matching a reference number is helpful, but the complete engine identification should be used for final fitment confirmation.
Is this an OEM part?
No. This listing is for an aftermarket replacement kit. The manufacturer references are provided for identification and cross-reference purposes only.
What should I do if the parts do not match my pump?
Do not force the parts into place or operate the engine with an incorrect pump component. Recheck the model, year, stroke, and serial number, then contact support before installation.
Safety & Important Information
- Verify the engine model, year, stroke, horsepower, and serial-number range before ordering.
- Compare the replacement components with the original parts before installation.
- Disconnect the battery and follow the engine manufacturer’s service and safety procedures.
- Do not operate the engine if the cooling-water flow is weak or the engine overheats.
- This is an aftermarket replacement kit, not an OEM component.
About Sea Sierra
- Pro-Grade Standards — We supply marine replacement parts selected for demanding real-world service conditions.
- Fast Global Fulfillment — Standard delivery options are available to most regions; available services and transit times are shown at checkout.
- Manufacturer-Direct Value — Practical aftermarket solutions for routine marine maintenance and repair.
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