Water Pump Impeller for Tohatsu/Nissan 40D & 50D 2-Stroke Outboards – Replaces 3C8-65021-2
Water Pump Impeller for Tohatsu/Nissan 40D & 50D 2-Stroke Outboards – Replaces 3C8-65021-2 is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Water Pump Impeller for Tohatsu/Nissan 40D & 50D 2-Stroke Outbo...
Water Pump Impeller for Tohatsu/Nissan 40D & 50D 2-Stroke Outboards – Replaces 3C8-65021-2 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller is intended for Nissan/Tohatsu 40D and 50D two-stroke outboard engines. It is a replacement impeller for the water pump and is designed to help restore the cooling-water flow required for normal engine operation.
The impeller is listed as a replacement for Tohatsu/Nissan OEM reference 3C8-65021-2, also shown as 3C8650212M. Sierra Marine reference 18-8922 is also listed for this impeller application.
- Single aftermarket water pump impeller.
- Application: Tohatsu/Nissan 40D and 50D two-stroke outboards.
- Designed as a replacement for the specified water-pump impeller application.
- Confirm the engine model and existing impeller reference before ordering.
Part Number Matrix
Use the following references when comparing your existing impeller and engine parts information. These numbers identify replacement or cross-reference listings; they do not replace verification of the complete engine model.
| Brand or Supplier | Reference | Type | Application Note |
|---|---|---|---|
| Tohatsu / Nissan | 3C8-65021-2 | OEM reference | Listed for the 40D and 50D two-stroke application. |
| Tohatsu / Nissan | 3C8650212M | OEM reference format | Alternate formatting of the specified Tohatsu/Nissan reference. |
| Sierra Marine | 18-8922 | Aftermarket cross-reference | Listed as the aftermarket reference for this impeller. |
| Mercury Mariner | 47-16154-2 | Company-listed reference | Shown in company catalog data for a 40–50 HP two-stroke application; verify against the engine and existing impeller before purchase. |
Engine Compatibility
The company catalog specifically identifies this product for Tohatsu/Nissan 40D and 50D two-stroke outboards. Engine model, stroke type, and the existing impeller reference must match before installation.
| Brand | Engine Model | Rated HP | Stroke | Reference | Fitment Guidance |
|---|---|---|---|---|---|
| Tohatsu / Nissan | 40D | 40 HP | 2-Stroke | 3C8-65021-2 | Company-listed application; verify the exact model designation before ordering. |
| Tohatsu / Nissan | 50D | 50 HP | 2-Stroke | 3C8-65021-2 | Company-listed application; verify the exact model designation before ordering. |
| Mercury Mariner | 40–50 HP application | 40–50 HP | 2-Stroke | 47-16154-2 | Company-listed reference; confirm the engine model and original impeller before purchase. |
Technical Specifications
- Product Type
- Water pump impeller
- Construction
- Rubber impeller
- Installation
- Replacement part for the specified water-pump application
- Primary Application
- Tohatsu/Nissan 40D and 50D two-stroke outboards
- Impeller Reference Dimensions
- Approximately A: 17.2 mm; B: 50.4 mm; C: 20.15 mm. Compare these measurements with the original part and pump housing before installation.
- Manufacturer Status
- Aftermarket replacement; not an OEM-manufactured component.
What's in the Box
- 1 x Water pump impeller
Important: The company record identifies this as a single impeller, not a kit. A key, gasket, water-pump housing, wear plate, and other service parts are not specified as included and should not be assumed to be included.
Installation Notes
- Confirm the engine model, two-stroke configuration, existing impeller reference, and impeller dimensions before disassembly.
- Remove the lower unit and water-pump cover according to the engine manufacturer's service procedure.
- Remove the old impeller and inspect the pump housing, wear plate, drive key, and sealing surfaces for wear or damage.
- Clean debris and corrosion from the pump components before installing the replacement impeller.
- Reuse only serviceable components, or replace the drive key, gaskets, and related parts when required by the engine service manual. These parts are not specified as included with this listing.
- Install the impeller in the correct direction and reassemble the water pump and lower unit using the manufacturer's torque specifications.
- Run the engine in an appropriate water supply and confirm a steady cooling-water discharge before returning the engine to service.
Troubleshooting & FAQ
Which engines is this impeller for?
The company catalog specifically lists Tohatsu/Nissan 40D and 50D two-stroke outboards. A company catalog entry also lists a Mercury Mariner 40–50 HP two-stroke reference. Match the exact engine model and existing impeller reference before ordering.
What references should I compare?
Compare your existing part with Tohatsu/Nissan 3C8-65021-2 or 3C8650212M and aftermarket reference Sierra 18-8922. Mercury Mariner reference 47-16154-2 is also listed in company data for a 40–50 HP two-stroke application and should be verified against your engine.
Is this an OEM part?
No. This listing is for an aftermarket replacement water pump impeller. The OEM numbers and supplier references are provided only for identification and compatibility comparison.
Does the package include a key or gasket?
No included key or gasket is specified. The company record identifies the product as one single impeller, so inspect and replace related water-pump service parts separately when required.
When should an impeller be inspected or replaced?
Inspect the impeller according to the engine manufacturer's maintenance schedule and whenever cooling-water flow is weak, the engine runs unusually hot, or the impeller shows cracking, hardening, deformation, or damaged vanes. Operating conditions such as sand, silt, and salt water can increase wear.
Safety & Important Information
- Do not rely on horsepower alone. Confirm the exact model, stroke type, impeller reference, and dimensions.
- Do not operate an outboard with inadequate cooling-water flow.
- Follow the engine manufacturer's service manual for removal, installation, torque values, and testing.
- This is an aftermarket replacement component and is not an OEM component.
- Professional installation is recommended if you are not familiar with outboard lower-unit or water-pump service.
About Sea Sierra
- Marine Replacement Parts — We provide replacement components for routine outboard maintenance and repair.
- Application-Focused Listings — Match the engine model, stroke type, and reference numbers before ordering.
- Practical Support — Use the product references and fitment information to select the correct service part for your engine.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
