Sierra 18-5819 Starter Solenoid, Replaces Mercury 89-818997A1, Fits Mercury 100 HP 4 Cyl. Outboards

The Sierra 18-5819 is a starter solenoid built for Mercury outboard engines, designed to deliver the high-current switching that engages the starter motor when the ignition key is turned. As the go-between for the low-current ignition circuit and the high-current starter circuit, the solenoid protects the ignition switch from the heavy amperage draw of the starter motor while ensuring a reliable, consistent start every time. Sierra engineers and builds this solenoid to meet or exceed the quality of the original equipment part it replaces, making it a dependable choice for engine owners performing a replacement or repowering an older Mercury outboard.

The 18-5819 measures 3 x 3 x 2.5 inches, is rated at 65 watts, and finished in white. It fits Mercury 100 HP 4 Cylinder outboards within a specific serial number range, and is cross-referenced to a wide range of OEM and aftermarket part numbers across Arco, Chrysler, GLM, Mallory, Mercury, and Yamaha, so it can be used as a direct swap for any of those numbers.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-5819
• Product Type: Starter Solenoid
• Item Dimensions: 3 x 3 x 2.5 inches
• Weight: 0.34 pounds
• Color: White
• Wattage: 65 watts
• OEM Cross-Reference: Arco SW097, Chrysler 89-818997A1, GLM 72402, Mallory 9-15115, Mercury 89-818997T1, Mercury 89-818997A, Mercury 89-818997A2, Yamaha 65W-81941-00-00, Yamaha 65W-81941-01-00

Fitment

• Mercury 100 HP 4 Cylinder outboards, serial numbers D252461 to G359967

Replaces (OEM)

• Arco SW097
• Chrysler 89-818997A1
• GLM 72402
• Mallory 9-15115
• Mercury 89-818997T1
• Mercury 89-818997A
• Mercury 89-818997A2
• Yamaha 65W-81941-00-00
• Yamaha 65W-81941-01-00

Frequently Asked Questions

What does the Sierra 18-5819 solenoid do? It switches the high-current circuit that engages the starter motor on a Mercury outboard, acting as the link between the ignition switch and the starter so the low-current key circuit is not exposed to the starter's heavy amperage draw.

Will the 18-5819 fit my Mercury outboard? The Sierra 18-5819 fits Mercury 100 HP 4 Cylinder outboards within the serial number range D252461 to G359967; check your engine's serial number tag against that range before ordering.

What OEM Mercury part numbers does the 18-5819 replace? It cross-references to Mercury 89-818997T1, 89-818997A, and 89-818997A2, so any of those OEM numbers can be replaced with the Sierra 18-5819.

Does this solenoid cross-reference to other brands besides Mercury? Yes, the Sierra 18-5819 also cross-references to Arco SW097, Chrysler 89-818997A1, GLM 72402, Mallory 9-15115, and Yamaha 65W-81941-00-00 and 65W-81941-01-00.

Is the Sierra 18-5819 genuine Mercury OEM or aftermarket? The 18-5819 is a Sierra-manufactured aftermarket solenoid built to meet or exceed the quality of the original Mercury equipment part it replaces, not a Mercury-branded OEM part.

What are the dimensions and weight of the 18-5819 solenoid? The 18-5819 measures 3 x 3 x 2.5 inches and weighs 0.34 pounds.

What color and wattage rating does this solenoid have? The Sierra 18-5819 is finished in white and carries a 65 watt rating.

Is the 18-5819 the same solenoid as the Sierra 18-5834? No, 18-5819 and 18-5834 are separate Sierra part numbers used across different Mercury outboard applications and serial ranges, so they are not interchangeable by default; confirm your engine's serial number to select the correct one.

What is included when I order the 18-5819? You receive one Sierra 18-5819 starter solenoid, ready to install in place of the OEM unit it replaces.

How do I know if my starter solenoid needs replacing? A failing solenoid on a Mercury outboard typically shows up as a clicking sound with no starter engagement, an intermittent or no-start condition, or a starter that stays engaged after the key is released; the Sierra 18-5819 is designed as a direct replacement for these symptoms on compatible 100 HP 4 Cylinder engines.