Water Pump Impeller Repair Kit – Fits Yamaha 4HP/5HP Outboard (Replaces 6E0-W0078-A2-00)
Water Pump Impeller Repair Kit – Fits Yamaha 4HP/5HP Outboard (Replaces 6E0-W0078-A2-00) 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 Repair Kit – Fits Yamaha 4HP/5HP Outboard (Repl...
Water Pump Impeller Repair Kit – Fits Yamaha 4HP/5HP Outboard (Replaces 6E0-W0078-A2-00) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Repair Kit – Fits Yamaha 4HP/5HP Outboard Motors (Replaces 6E0-W0078-A2-00) provides the necessary components to service the lower unit water pump on Yamaha 2-stroke 4HP (1984–1999) and 5HP (1984–2002) models, as well as 4-stroke F4 (1999–2008) outboards.
The kit serves as a direct replacement for Yamaha equivalents 6E0-W0078-A2-00, 6E0-W0078-02-00, 6E0-W0078-01-00, 6E0-W0078-00-00, and Sierra 18-3016.
- Direct replacement fit for straightforward installation.
- Constructed with a durable neoprene rubber impeller and stainless steel housing plates.
- Kit includes all essential gaskets, seals, and hardware for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6E0-W0078-A2-00 |
| Yamaha | 6E0-W0078-02-00 |
| Yamaha | 6E0-W0078-01-00 |
| Yamaha | 6E0-W0078-00-00 |
| Sierra | 18-3016 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha Engines: This kit fits a range of 4HP and 5HP 2-stroke models produced from 1984 onwards, plus 4-stroke F4 models from 1999–2008.
For Mariner Engines: Compatibility is limited to specific 4A and 5C models using serial numbers beginning with 6E0 or 6E3. Verify your engine's serial before ordering.
| Brand | Model | Rated HP | Stroke | Years | Notes |
|---|---|---|---|---|---|
| Yamaha | 4A, 4AC, 4ACMH, 4CMH | 4 | 2-Stroke | 1984–1999 | |
| Yamaha | 4MLHU, 4MLHU2, 4MSHU, 4MSHU2 | 4 | 2-Stroke | 1996 | |
| Yamaha | 5C, 5CM, 5CMH | 5 | 2-Stroke | 1984–2002 | |
| Yamaha | 5MLHU, 5MLHU2, 5MSHU, 5MSHU2 | 5 | 2-Stroke | 1996 | |
| Yamaha | F4 | 4 | 4-Stroke | 1999–2008 | |
| Mariner | 4A(6E0) | 4 | 2-Stroke | Models with Serial Number 6E0 | |
| Mariner | 5C(6E3) | 5 | 2-Stroke | Models with Serial Number 6E3 | |
| Mariner | 96325T, 96325M | 4, 5 | 2-Stroke | Only with Serial Number 6E0 & 6E3 |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Direct replacement
- Materials
- Neoprene rubber impeller, stainless steel plates
- Dimensions
- 152 × 102 × 51 mm (6 × 4 × 2 inches)
- Weight
- 0.18 kg (0.4 lb)
- Design
- High-quality materials designed to OEM specifications
What’s in the Box
- 1 x Water Pump Housing (6E0-44311-00-00)
- 1 x Water Pump Gasket (6E0-44315-A0-00)
- 1 x Cartridge Insert (6E0-44322-02-00)
- 1 x Cartridge Outer Plate (6E0-44323-00-00)
- 1 x Impeller (6E0-44352-00-00)
- 1 x Water Seal Damper 2 (6E0-44366-00-00)
- 1 x Dowel Pin (93604-09066-00)
- 4 x Bolt (97080-06045-00/97095-06045-00)
Installation Notes
- Disconnect the negative battery cable and remove the engine cover.
- Shift the outboard into neutral and remove the lower unit mounting bolts.
- Carefully lower and separate the gearcase from the upper driveshaft housing.
- Locate and unbolt the water pump housing, noting the orientation of the old parts.
- Remove the old impeller, gaskets, and wear plates. Clean all mating surfaces thoroughly.
- Install the new gasket, wear plate, and cartridge insert from the kit.
- Slide the new impeller onto the driveshaft, rotating it clockwise to seat the vanes correctly.
- Install the new housing and torque the bolts to the manufacturer's specification.
- Reassemble the lower unit to the engine, ensuring the driveshaft and water tube align.
- Reconnect the battery and test operation in a safe water environment, confirming a strong water stream.
Troubleshooting & FAQ
How do I know if this kit fits my specific engine?
First, check the compatibility table. If your engine’s brand, model, HP, and year range are listed, it should fit. For absolute certainty, cross-reference your existing part number with those in the Part Number Matrix.
What are the signs of a failing water pump impeller?
The most common signs are a weak or non-existent water stream from the tell-tale port, frequent engine overheating alarms, and in severe cases, steam from the exhaust. Reduced engine performance can also indicate a cooling problem.
How often should I replace my water pump impeller?
As a preventative maintenance measure, we recommend replacing the impeller every one to two years, or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).
What is the difference between this kit and an OEM one?
This is an aftermarket replacement part, not an OEM component. It is designed to meet or exceed original equipment manufacturer (OEM) specifications for fit, form, and function, offering a high-quality, cost-effective alternative.
How fast is shipping and what does it cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free on most orders, with expedited options available at checkout for an additional fee.
What warranty and return policy applies?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter an issue, contact support with your order details. Returns are accepted within our standard window for unused items in their original condition. Please see our full policy page or contact us 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.
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.
