Sierra 18-3050 Impeller with Key for Johnson/Evinrude 2.5, 3, 4, Ultra, Excel Outboards, Replaces OMC 386084

The Sierra 18-3050 is a water pump impeller designed for Johnson/Evinrude (OMC/BRP) outboards, fitting the 2.5, 3, and 4 horsepower models as well as the Ultra and Excel lines. The impeller is the wear component inside the outboard's water pump housing that draws raw water in to cool the engine, and it is one of the most common maintenance replacement parts on a small outboard. This unit ships with a key included, so it is ready to install alongside the pump housing, gaskets, and other water pump service parts without needing to source the key separately. The impeller body is made of alloy steel. As a Sierra part, the 18-3050 is built as a direct equivalent to the OMC impeller it replaces, letting owners restore proper cooling water flow using a part number matched to the original engine specification rather than a generic substitute. Because a worn or cracked impeller is a leading cause of overheating on small outboards, keeping a correctly sized replacement like the 18-3050 on hand is a standard part of routine outboard maintenance for the 2.5, 3, and 4 HP Johnson/Evinrude Ultra and Excel models.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3050
• Type: Impeller
• Included Components: Impeller, Key
• Material: Alloy Steel
• Color/Finish: Unfinished
• Weight: 0.05 pounds
• OEM Cross Reference: OMC 386084
• UPC: 030999237156

Fitment

• Johnson/Evinrude (OMC/BRP) outboards: 2.5, 3, 4 HP, Ultra, Excel

Replaces (OEM)

• OMC 386084

Frequently Asked Questions

What outboards does the Sierra 18-3050 impeller fit? The Sierra 18-3050 is designed for Johnson/Evinrude (OMC/BRP) outboards rated 2.5, 3, and 4 horsepower, as well as the Ultra and Excel models.

Is the 18-3050 a direct OEM replacement? Yes, the Sierra 18-3050 replaces OMC part number 386084, making it a direct equivalent for that OEM impeller.

Does the impeller come with the key needed for installation? Yes, the 18-3050 ships with a key included, so it is ready to install without sourcing the key separately.

What material is the 18-3050 impeller made of? The Sierra 18-3050 impeller is made of alloy steel.

How much does the 18-3050 impeller weigh? The Sierra 18-3050 impeller weighs 0.05 pounds.

What color or finish does the 18-3050 impeller have? The 18-3050 has an unfinished color/finish, as supplied from the factory.

What is included when I order the 18-3050? Ordering the Sierra 18-3050 gets you the impeller plus the installation key.

Why would I need to replace this impeller? A worn, cracked, or brittle impeller reduces raw water flow and is a common cause of overheating in small Johnson/Evinrude outboards, so replacing the 18-3050 on schedule keeps the cooling system working properly.

Is the Sierra 18-3050 the same part as the 18-3051 impeller? No, the 18-3050 and 18-3051 are separate Sierra part numbers replacing different OEM impellers, so buyers should confirm which OEM number their engine calls for before ordering.

Does the 18-3050 impeller work for both port and starboard installations? The 18-3050 is a water pump impeller and is not a side-specific part; it is used within the outboard's single water pump housing rather than mounted on a specific side.

What brand makes the 18-3050 impeller? The 18-3050 impeller is manufactured by Sierra.

What UPC is associated with the Sierra 18-3050? The Sierra 18-3050 impeller carries UPC 030999237156.