Sierra 18-5620 Outboard Starter – Replaces 50-818445-2

The Sierra 18-5620 Outboard Starter is a premium aftermarket replacement starter motor designed specifically for high-power Mercury and Mariner outboard engines. It is engineered to meet or exceed original equipment manufacturer (OEM) specifications, offering marine-grade corrosion resistance, specialized seals to prevent water intrusion, and reliable ignition in demanding saltwater environments.

Key Specifications

• Rotation: Clockwise (Right)
• Tooth Quantity: 8 teeth on the starter drive
• Voltage: 12V DC
• Housing Material: Aluminum with an anti-corrosion outer coating
• Mounting Design: 3-bolt hole bracket configuration

Engine Compatibility

This starter motor fits a range of larger V6 block engines, primarily encompassing:

• Mercury / Mariner 2.5L, 3.0L, and 225–250 HP models built between 1993 and 2000.
• Selected late-model 225 HP EFI / Magnum configurations running from 1994 and up.

OEM Interchange Parts

In addition to replacing the 50-818445-2 part number, this assembly is a direct interchangeable substitute for the following OEM and marine aftermarket part numbers:

• Mercury Marine: 50-818445, 50-818445-3, 50-818445-5, and 50-898265009
• Arco Marine: 5395
• Mallory Marine: 9-15028

Important Fitment Information

Outboard starter compatibility can vary depending on the engine model, year, horsepower, mounting configuration, and original starter specifications. Before ordering, compare the original starter and verify the OEM part number, mounting pattern, starter drive gear, tooth count, voltage, and rotation for your specific engine.

Shop the Sierra 18-5620 Outboard Starter at U.S. Boating & Marine Supplies for replacement marine starters, outboard electrical components, and boat engine parts.