Sierra 3050 Johnson/Evinrude Impeller

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 19952004
• 9.9 HP two-stroke models, approximately 19742006
• 15 HP two-stroke models, approximately 19742006
• 9.9 HP four-stroke models, approximately 19952001
• 15 HP four-stroke models, approximately 19952001

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 23 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 4075HP
• Sierra Marine Water Pump Kit 18-3390 Johnson/Evinrude 85300HP 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.