Sierra 3050 Johnson/Evinrude Impeller
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You have 30 days to request a return. All sale items are final sale.
The Sierra 3050 (18-3050) Impeller is a direct-fit replacement water pump impeller for Johnson and Evinrude outboard engines. Built to OEM specifications, this neoprene impeller restores proper cooling water circulation through the lower unit water pump, preventing powerhead overheating on smaller displacement J/E outboards.
Key Features
- Sierra aftermarket replacement water pump impeller
- Sierra part number 18-3050
- Replaces Johnson/Evinrude and OMC 386084 / 0386084
- Six flexible impeller blades
- Neoprene-style rubber construction
- Corrosion-resistant metal hub
- Installs in the outboard lower-unit water pump
- Approximate outside diameter: 38.4 mm / 1.51 inches
- Approximate shaft opening: 12.75 mm / 0.50 inch
- Impeller only; housing, plate, key and gaskets are not identified as included
Engine Compatibility
The Sierra 18-3050 is commonly associated with compatible Johnson and Evinrude outboards using OEM impeller 386084, including:
- 8 HP four-stroke models, approximately 1995–2004
- 9.9 HP two-stroke models, approximately 1974–2006
- 15 HP two-stroke models, approximately 1974–2006
- 9.9 HP four-stroke models, approximately 1995–2001
- 15 HP four-stroke models, approximately 1995–2001
Parts Desk Insight — Best Use
This impeller is the correct service part for routine water pump maintenance on Johnson/Evinrude outboards in the smaller horsepower range. Best practice is to replace the impeller every 2–3 seasons or 200 hours of operation — whichever comes first — regardless of visible wear. Impeller vanes harden and lose flexibility over time without showing obvious external damage, which reduces cooling flow and risks engine overheating. Always replace during lower unit service or anytime the gearcase is opened.
Tip: For a complete water pump service, pair this impeller with a full water pump repair kit that includes the housing, wear plate, gaskets, and seals. Confirm fitment against your engine model and year before ordering.
Compatible Water Pump Kits
- Sierra Marine Water Pump Kit 18-3380 – Johnson/Evinrude 40–75HP
- Sierra Marine Water Pump Kit 18-3390 – Johnson/Evinrude 85–300HP V4/V6
Related Impellers
- Sierra 3051 (18-3051) Johnson/Evinrude Impeller
- Sierra 3058 Johnson/Evinrude Impeller
- Sierra 3059 Johnson/Evinrude Impeller
- Sierra 31041 Johnson/Evinrude Impeller
Refer to the Sierra Marine catalog or your engine service manual to confirm fitment for your specific engine model and year.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.