Water Pump Impeller 386084 – Fits Johnson Evinrude OMC BRP 8HP 9.9HP 10HP 15HP Outboard Motors
This replacement water pump impeller is designed for Johnson, Evinrude, OMC, and BRP outboard motors rated 8HP, 9.9HP, 10HP, and 15HP. Engineered to restore optimal cooling performance, this impeller ensures reliable operation and easy maintenance for your outboard engine.
This impeller directly replaces OEM part number 386084 and crosses to popular aftermarket numbers including Sierra 18-3050 and CEF 500355, providing broad compatibility and proven reliability.
- High-performance neoprene rubber construction for durability and chemical resistance
- Includes impeller with key/pin for complete installation
- 6-blade design for efficient water flow and cooling
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
Notes |
| Johnson / Evinrude / OMC / BRP |
386084, 0386084 |
OEM |
| Sierra |
18-3050 |
Aftermarket |
| CEF |
500355 |
Aftermarket |
Compatible Engine Models
Confirm your engine model/year in the table below. For Johnson/Evinrude owners, here's a guide to help you identify your engine's serial/model: Johnson Serial Number Guide.
| Brand |
Rated HP |
Notes |
| Johnson / Evinrude / OMC / BRP |
8HP, 9.9HP, 10HP, 15HP |
Outboard Motors |
Technical Specifications
| Specification |
Value |
| Material |
Marine and chemical corrosion resistant metal alloy with high-performance neoprene rubber |
| Number of Blades |
6 |
| External Impeller Overall Diameter |
38.40 mm |
| Internal Shaft Insert Diameter |
12.75 mm |
| Item Weight |
Approximately 17 g |
| OEM Replacement For |
Johnson / Evinrude 386084 (9.9/15 HP) |
Package Contents
- 1 × Outboard Rubber Impeller with Key / Pin
Installation Guide
- Disconnect the fuel line and remove the engine cowling to access the lower unit. Ensure the engine is completely cool before beginning work.
- Remove the propeller and drain the lower unit gear oil. Disconnect the water pump housing bolts and carefully separate the lower unit from the mid-section.
- Remove the old impeller from the water pump housing, noting the direction of the blade curvature. Clean the housing thoroughly and inspect for wear or damage.
- Lubricate the new impeller with water pump grease or glycerin. Insert the key/pin into the driveshaft slot as indicated.
- Install the new impeller onto the driveshaft, rotating it in the correct direction to match the original blade orientation. Ensure all blades are properly seated.
- Reassemble the water pump housing and lower unit, torquing all bolts to manufacturer specifications. Refill the lower unit with fresh gear oil.
- Reinstall the propeller and engine cowling. Start the engine and verify strong water flow from the telltale outlet to confirm proper operation.
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my Johnson or Evinrude engine?
A: Verify your engine's horsepower rating (8HP, 9.9HP, 10HP, or 15HP) and cross-check the OEM part number 386084 in your service manual or parts diagram. The compatible engine table above lists the applicable models.
Q: How often should I replace my water pump impeller?
A: Most manufacturers recommend replacing the impeller every 2–3 years or 200–300 hours of operation, whichever comes first. If you notice reduced water flow, overheating, or visible blade damage, replace it immediately.
Q: What are the signs of a failing impeller?
A: Common symptoms include weak or no water discharge from the telltale outlet, engine overheating, steam from the exhaust, or visible cracks and missing blade tips. Inspect the impeller annually even if no symptoms are present.
Q: Can I use this impeller in saltwater environments?
A: Yes, this impeller is constructed from marine-grade neoprene rubber and corrosion-resistant materials designed for both freshwater and saltwater use. Rinse the cooling system with freshwater after each saltwater outing to extend impeller life.
Q: What is the difference between this aftermarket impeller and the OEM part?
A: This is an aftermarket replacement part built to OEM specifications using comparable-grade materials. It is not an OEM component. We manufacture in an ISO9002-certified facility and inspect each batch for consistent performance and fitment.
Q: Do I need any special tools to install this impeller?
A: Basic hand tools (wrenches, screwdrivers) and a torque wrench are recommended. Water pump grease or glycerin for lubrication is also helpful. Refer to your engine's service manual for specific torque values and procedures.
Q: Is this an OEM part or an aftermarket replacement?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.