Description

The Sierra 18-3543 Thermostat is designed for Johnson and Evinrude outboard applications and provides reliable temperature regulation to support consistent engine performance. With a 143°F temperature rating, it helps maintain proper operating conditions within the marine cooling system for improved efficiency and protection. This thermostat is interchangeable with Johnson/Evinrude part numbers 378065, 393659, 434841, 437414, 5005440, and 508626, offering broad compatibility across multiple engine setups. Each unit is engineered to meet or exceed original equipment specifications, ensuring dependable fit, durability, and performance in marine environments.

Features

143°F temperature rating designed to maintain stable engine operating conditions
Compatible with Johnson and Evinrude outboard applications for broad marine use
Interchangeable with OE part numbers 378065, 393659, 434841, 437414, 5005440, and 508626
Engineered to meet or exceed original equipment performance standards
Supports consistent cooling system regulation for reliable marine engine operation
For Johnson/Evinrude outboards
Premium quality for longer life
Meets or exceeds manufacturer specs
Backed by Sierra’s limited lifetime warranty