Sierra 18-3043 Impeller - Replaces OMC 389642, Fits 140/150/175 HP Evinrude/Johnson Outboards

The Sierra 18-3043 Impeller is a replacement water pump impeller engineered to meet or exceed original equipment quality for select Evinrude/Johnson outboard motors. As the rotating component inside the outboard's water pump, the impeller draws raw water through the lower unit and pushes it up to cool the powerhead, making it a critical wear item for reliable engine operation. The impeller is constructed of a durable elastomer body bonded to a metal insert, with a black finish, and is built to the fit and tolerances of the original part it replaces.

This impeller is designed for 140 HP outboards from 1977-78, and 150 HP and 175 HP outboards from 1976-78. It directly interchanges with several original equipment and aftermarket cross-reference numbers, so it can be ordered using either the Sierra part number or a known OEM equivalent. Because water pump impellers wear over time and can fail without warning, causing overheating, replacing the 18-3043 on a regular service interval or at the first sign of reduced water flow helps protect the engine from heat-related damage.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3043
• Item Type: Impeller
• Material: Aluminum, Stainless Steel
• Color: Black
• UPC: 030999315052
• Weight: 0.35 pounds
• Unit Count: 1
• OEM Cross Reference: GLM 89680, Evinrude/Johnson 389642, 777212, 385528, Mallory 9-45203, OMC 389642

Fitment

• Evinrude/Johnson 140 HP outboards, 1977-78
• Evinrude/Johnson 150 HP outboards, 1976-78
• Evinrude/Johnson 175 HP outboards, 1976-78

Replaces (OEM)

• GLM 89680
• Evinrude/Johnson 389642
• 777212
• 385528
• Mallory 9-45203
• OMC 389642

Frequently Asked Questions

What does the Sierra 18-3043 impeller fit? The Sierra 18-3043 fits Evinrude/Johnson 140 HP outboards from 1977-78, and 150 HP and 175 HP outboards from 1976-78.

Is the 18-3043 interchangeable with OEM part numbers? Yes, the 18-3043 cross-references to OMC 389642, GLM 89680, Evinrude/Johnson 389642, 777212, 385528, and Mallory 9-45203, so it can be ordered under any of those equivalent numbers.

What material is the 18-3043 impeller made of? This impeller is made of aluminum and stainless steel components with a black finish, built to meet or exceed the quality of the original equipment part.

How much does the Sierra 18-3043 impeller weigh? The Sierra 18-3043 impeller weighs 0.35 pounds.

How many impellers come in a package of the 18-3043? The 18-3043 is sold as a single impeller, with a unit count of 1.

Does the 18-3043 fit 1976 model year 140 HP outboards? No, the 18-3043 is designated for 140 HP outboards from 1977-78; the 1976 model year is not covered by this part number.

Is the Sierra 18-3043 an OEM or aftermarket part? The 18-3043 is a Sierra-branded aftermarket impeller manufactured to meet or exceed the quality of the original OMC 389642 equipment part it replaces.

What is the UPC for the Sierra 18-3043 impeller? The UPC for the Sierra 18-3043 impeller is 030999315052.

Why does a water pump impeller need to be replaced? An impeller like the 18-3043 wears down over time from friction and heat, and a worn impeller reduces raw water flow to the engine, which can lead to overheating; replacing it at regular intervals or when water flow drops helps prevent engine damage.

Does the 18-3043 fit both 150 HP and 175 HP outboards? Yes, the 18-3043 fits 150 HP and 175 HP Evinrude/Johnson outboards from 1976-78, in addition to 140 HP models from 1977-78.