Water Pump Impeller Service Kit for Mercury 25–30 HP 4-Stroke EFI and Compatible Tohatsu/Nissan Outboards — Replaces 853792A07 and 361-87322-0
Water Pump Impeller Service Kit for Mercury 25–30 HP 4-Stroke EFI and Compatible Tohatsu/Nissan Outboards — Replaces 853792A07 and 361-87322-0 is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Service Kit for Mercury 25–30 HP 4-Stroke EFI a...
Water Pump Impeller Service Kit for Mercury 25–30 HP 4-Stroke EFI and Compatible Tohatsu/Nissan Outboards — Replaces 853792A07 and 361-87322-0 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller service kit is designed for selected Mercury, Mariner and Force 25–30 HP 4-stroke EFI outboards and compatible Tohatsu/Nissan applications. It is intended to restore water-pump performance and help maintain proper engine cooling when the existing impeller, gasket, wear components or related service parts are worn.
The kit is listed as a replacement for Mercury reference numbers 853792A07, 853792A1 and 853792T01, together with Tohatsu/Nissan references 361-87322-0, 361873220M and 361873220. These numbers should be compared with the number and configuration of the parts removed from your engine before ordering.
- Aftermarket water pump impeller service kit for selected outboard applications.
- Includes an impeller and related water-pump service components listed below.
- Designed for direct replacement where the listed reference number and engine conditions match.
- Impeller reference 345-65021-0 is cataloged for selected 25–30 HP Tohatsu applications and related 25–35 HP impeller applications; complete kit fitment remains dependent on the engine model and water-pump assembly.
Part Number Matrix
Use the following references to compare the kit with the part being replaced. A reference number alone does not confirm fitment for every engine variant.
| Brand or Type | Part Number |
|---|---|
| Mercury | 853792A07 |
| Mercury | 853792A1 |
| Mercury | 853792T01 |
| Tohatsu / Nissan | 361-87322-0 |
| Tohatsu / Nissan | 361873220M |
| Tohatsu / Nissan | 361873220 |
| Aftermarket impeller reference | 345-65021-0 |
| Aftermarket impeller reference | 47-16154-1 |
| Aftermarket impeller reference | 161541 |
Engine and Model Compatibility
Confirm the complete engine model, stroke, production year and serial-number range before installation. Mercury fitment is commonly controlled by serial number rather than year alone. The model entries below are application leads and should be checked against the service-manual diagram or the original water-pump parts before purchase.
| Brand | Model | Rated HP | Stroke | Years / Serial No. | Reference |
|---|---|---|---|---|---|
| Mercury | Sea Pro | 25 | 4-Stroke | 0R051710 and up | 853792A07 |
| Mercury | EFI Standard | 25 | 4-Stroke | 0R106999 and up | 853792A07 |
| Mercury | EFI JET | 25 | 4-Stroke | 0R165086 and up | 853792A07 |
| Mercury | EFI Standard | 30 | 4-Stroke | 0R106999 and up | 853792A07 |
| Tohatsu | M25C2 | 25 | 2-Stroke | 1996–2005 | 361-87322-0 |
| Tohatsu | M25C3 | 25 | 2-Stroke | 2002–2005 | 361-87322-0 |
| Tohatsu | M30A3 | 30 | 2-Stroke | 1996–2002 | 361-87322-0 |
| Tohatsu | M30A4 | 30 | 2-Stroke | 2002–2005 | 361-87322-0 |
| Tohatsu | M35C | 35 | 2-Stroke | 2002 | 361-87322-0 |
| Tohatsu | M40C | 40 | 2-Stroke | 1996–2004 | 361-87322-0 |
| Nissan | NS25C2 | 25 | 2-Stroke | 1996–2002 | 361-87322-0 |
| Nissan | NS25C3 | 25 | 2-Stroke | 2002–2005 | 361-87322-0 |
| Nissan | NS30A3 | 30 | 2-Stroke | 1996–2002 | 361-87322-0 |
| Nissan | NS30A4 | 30 | 2-Stroke | 2002–2005 | 361-87322-0 |
| Nissan | NS35C | 35 | 2-Stroke | 2002 | 361-87322-0 |
| Nissan | NS40C | 40 | 2-Stroke | 1996–2004 | 361-87322-0 |
| Nissan | NS40C2 | 40 | 2-Stroke | 2002–2004 | 361-87322-0 |
| Tohatsu / Nissan | Selected 25–30 HP models | 25–30 | 4-Stroke | Verify exact model and year | Check the complete water-pump assembly |
Technical Specifications
- Product Type
- Water pump impeller service kit
- Installation
- Replacement water-pump service component
- Application
- Selected gasoline outboard engines
- Impeller Material
- Marine-grade neoprene rubber
- Included Service Materials
- Gaskets and metal water-pump service components as listed below
- Impeller Color
- Black
- Approximate Weight
- 130 g (4.6 oz), as listed
- Product Status
- Aftermarket replacement; not an OEM-manufactured component
What's in the Box
- 1 x Water pump impeller, reference 345-65021-0 / 47-16154-1 / 161541
- 1 x Impeller key, reference 28-161582 / 348-65018
- 1 x Gasket, reference 278-161602 / 348-65029-1
- 1 x Gasket, reference 27-161582 / 348-65018-0
- 1 x Insert cup, reference 161572 / 348-65011-0
- 1 x Wear plate, reference 161592 / 348-65025-0
- 4 x Bolts and washers, reference 910103-565
Package contents may vary by production batch. Compare the supplied components with the water-pump parts removed from your engine before beginning installation.
Installation Notes
- Disconnect the battery and remove the engine cover where applicable.
- Place the engine securely and remove the lower unit according to the manufacturer's service procedure.
- Remove the water-pump housing and retain the original fasteners for comparison.
- Remove the old impeller, key, gaskets, cup and wear plate as applicable.
- Clean the mating surfaces and inspect the housing, drive key, shaft and fasteners for wear or corrosion.
- Install the replacement components in the same order as the original parts, with the impeller key correctly seated.
- Lubricate the impeller and housing with a suitable water-pump assembly lubricant; do not use petroleum products that may damage the rubber.
- Reassemble the water pump and lower unit. Tighten fasteners to the engine manufacturer's specifications.
- Test-run the engine in an appropriate water supply and confirm a steady tell-tale stream before normal operation.
Troubleshooting and FAQ
How do I confirm fitment for a Mercury engine?
Use the engine's complete model and serial number. Compare the serial range, water-pump diagram and original part number rather than relying on horsepower alone.
What are common signs of a worn impeller?
Symptoms can include a weak or missing tell-tale stream, overheating warnings, fluctuating cooling-water flow, or a damaged, melted or deformed impeller.
How often should the impeller be inspected?
Inspect the impeller during scheduled maintenance and replace it when damaged, hardened, cracked or deformed. Service intervals depend on operating hours, storage conditions and saltwater exposure; follow the engine manufacturer's maintenance schedule.
Will this fit every Tohatsu or Nissan 25–40 HP engine?
No. Tohatsu and Nissan engines can use different water-pump designs across model, year and serial-number ranges. Verify the exact model, stroke and original water-pump reference before ordering.
Is this an OEM part?
No. This is an aftermarket replacement kit intended to replace the listed OEM and manufacturer reference numbers where the application matches.
What should I do if my original components look different?
Do not force installation. Compare the complete water-pump assembly, shaft key, housing, cup, wear plate and gasket pattern with the supplied parts before use.
Safety and Important Information
- Verify the engine model, year, stroke, serial number and original part number before purchase.
- Do not operate an outboard without a reliable cooling-water supply.
- Use appropriate lifting, support and lower-unit removal procedures.
- Professional installation is recommended if you are unfamiliar with outboard lower-unit service.
- This is an aftermarket replacement, not an OEM component.
About Sea Sierra
- Pro-Grade Standards — Marine replacement parts selected for dependable service in real-world operating conditions.
- Global Fulfillment — Standard and expedited delivery options are shown at checkout where available.
- Manufacturer-Direct Value — Practical replacement solutions with clear application and part-number information.
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