Sierra 18-3569 Marine Engine Thermostat Kit

The Sierra 18-3569 Thermostat Kit is engineered specifically for Mercury and Mariner 2-stroke outboard motors ranging from 70 to 125 HP (1987 and newer models). This complete replacement kit ensures your outboard engine operates at optimal temperature for maximum performance and efficiency.

Complete Kit Includes:

• 18-3549 Thermostat (120°F/49°C temperature rating)
• 18-0182 Thermostat Gasket
• 18-0339 Thermostat Cover Gasket

Key Features:

• Meets or exceeds OEM specifications for reliable performance
• Direct replacement for Mercury Marine part number 803061T1
• Compatible with multiple engine models: 70, 75, 80, 90 HP (3-cylinder) and 100, 115, 125 HP (4-cylinder)
• All components included for complete installation—no need to source individual parts
• Also replaces GLM 13124, Mallory 9-43155, and Pro Marine 8032

A properly functioning thermostat is essential for maintaining the correct operating temperature in your outboard motor. Running outside the optimal temperature range can lead to reduced performance, decreased fuel efficiency, and potential engine damage. Sierra Marine products are designed to restore function to OEM specifications, ensuring your engine runs at peak performance.