Sierra 18-3368 Water Pump Impeller for Johnson/Evinrude 50 HP Outboard, 1986-88 (Replaces OMC 396809)

The Sierra 18-3368 is a neoprene water pump impeller built for Johnson/Evinrude 50 HP outboard motors from the 1986-88 model years. As the impeller wears, it loses the flexibility needed to draw and push cooling water through the powerhead, leading to overheating and potential engine damage; replacing it on schedule keeps raw water circulating properly and protects the block, exhaust, and cylinder head from heat-related failure.

This impeller uses a 6-fin neoprene design engineered to meet or exceed the specifications of the original equipment part it replaces. Neoprene is the standard material for outboard water pump impellers because it holds its shape and seal under repeated flexing while running dry-start conditions common to marine engines. The impeller is finished in white and is sold as a single component, so it pairs with the water pump plate, housing, or full repair kit already on the engine rather than including those parts.

Sierra manufactures replacement parts for OEM engine builders and boat manufacturers, and the 18-3368 is cross-referenced to the OMC/Evinrude/Johnson part numbers used on this water pump application, making it a straightforward like-for-like swap during a routine water pump service.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3368
• Material: Neoprene
• Color: White
• Number of Fins: 6
• Weight: 0.15 pounds
• Engine Fitment: Johnson/Evinrude 50 HP outboard, 1986-88
• UPC: 030999753502

Fitment

• Johnson/Evinrude 50 HP outboard, 1986-88

Replaces (OEM)

• GLM 89780
• Evinrude/Johnson 39809
• 777214
• Mallory 9-45208
• OMC 396809

Frequently Asked Questions

What engine does the Sierra 18-3368 impeller fit? The Sierra 18-3368 is designed for Johnson/Evinrude 50 HP outboard motors from the 1986-88 model years.

Is the 18-3368 the same as OMC 396809? Yes, OMC 396809 is a listed OEM equivalent to the Sierra 18-3368 impeller, so it fits the same 50 HP Johnson/Evinrude water pump application.

What material is the impeller made from? It is molded from neoprene, the standard flexible material used in outboard water pump impellers to withstand repeated flexing and dry-start conditions.

How many fins does the 18-3368 impeller have? This impeller has 6 fins, matching the original design used in the Johnson/Evinrude 50 HP water pump.

What color is the Sierra 18-3368 impeller? The 18-3368 is white, which is the standard color for this neoprene impeller.

Is this a genuine Sierra part? Yes, part number 18-3368 is manufactured by Sierra and built to meet or exceed the original equipment part it replaces.

Does the 18-3368 include the water pump housing or gasket? No, the 18-3368 is the impeller only; the housing, plate, and gasket are separate components sold individually or as part of a full pump kit.

What OEM and aftermarket numbers cross-reference to this impeller? The Sierra 18-3368 cross-references to GLM 89780, Evinrude/Johnson 39809, 777214, Mallory 9-45208, and OMC 396809.

How much does the 18-3368 impeller weigh? The Sierra 18-3368 impeller weighs 0.15 pounds.

How do I know if I need just the impeller or a full repair kit? If only the rubber impeller has worn or lost its fins, the 18-3368 alone is sufficient; if the housing, plate, or seals are also damaged, a complete water pump repair kit for the 1986-88 50 HP Johnson/Evinrude is the better choice.

What is included when I order the 18-3368? You receive one Sierra 18-3368 neoprene impeller; no housing, plate, gasket, or hardware is included.