Sierra 18-6420 Outboard Starter Motor for Yamaha Outboard Motors

The Sierra 18-6420 is a marine-grade replacement outboard starter motor engineered for select Yamaha outboard engines. Built to meet or exceed original equipment manufacturer (OEM) standards, this aftermarket starter delivers reliable cranking power while standing up to the harsh demands of the marine environment.

Key Features:

• Marine-grade construction meets SAE J1171 and ISO 8846 standards
• High-quality magnets and field coils provide superior starting torque
• Double-sealed housing protects internal components from water and moisture intrusion
• Premium brushes engineered for extended service life
• Manufactured to meet or exceed all OEM requirements
• Limited lifetime warranty

OEM Cross-Reference Numbers:

• Yamaha: 6L2-81800-20-00, 682-81800-11-00, 682-81800-12-00, 6L2-81800-10-00, 6L2-81800-11-00
• Arco: 3421

For proper installation, use with Starter Drive Assembly Sierra 18-5658. Sierra has been a trusted name in the marine aftermarket industry for over 50 years, delivering engine and drive parts that protect your investment on the water.