Sierra 18-3569 Marine Thermostat Kit, 120 F, for Mercury/Mariner 70-125 HP 2 Cycle Outboards 1987 and Newer

The Sierra 18-3569 Thermostat Kit is a complete cooling-system repair kit for Mercury and Mariner 2 cycle outboard motors. It is built around a 120 F rated thermostat and includes the gaskets needed for a proper reinstall, so the job can be done in one pass without hunting down separate gasket parts. Marine thermostats regulate engine operating temperature by controlling coolant flow, and a stuck or worn unit is a common cause of overheating or slow warm-up in outboard motors -- this kit lets you replace the thermostat and both related gaskets together.

The kit includes one 18-3549 thermostat, one 18-0182 thermostat gasket, and one 18-0339 thermostat cover gasket. It is designed to fit various Mercury/Mariner 70-125 HP 2 cycle outboards from 1987 and newer. Sierra manufactures its cooling components to meet or exceed the specifications of the original equipment they replace, making this kit a straightforward like-for-like replacement for the factory thermostat assembly.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3569
• Product Name: Thermostat Kit
• Thermostat Temperature Rating: 120 F
• Included Components: 1 x 18-3549 Thermostat, 1 x 18-0182 Thermostat Gasket, 1 x 18-0339 Thermostat Cover Gasket
• Weight: 0.08 pounds
• UPC: 808282112899

Fitment

• Various Mercury/Mariner 70-125 HP 2 cycle outboards, 1987 and newer

Replaces (OEM)

• GLM 13124
• Mallory 9-43155
• Mercury Marine 803061T1

Frequently Asked Questions

What does the Sierra 18-3569 Thermostat Kit include? The kit includes one 18-3549 thermostat, one 18-0182 thermostat gasket, and one 18-0339 thermostat cover gasket, so both gaskets needed for the reinstall are included along with the thermostat itself.

What outboards does the 18-3569 thermostat kit fit? It fits various Mercury/Mariner 70-125 HP 2 cycle outboards, 1987 and newer.

What temperature is the thermostat in kit 18-3569 rated for? 120 F is the temperature rating of the thermostat included in the Sierra 18-3569 kit.

Is the Sierra 18-3569 kit interchangeable with OEM Mercury Marine parts? Yes, it is interchangeable with Mercury Marine 803061T1, as well as GLM 13124 and Mallory 9-43155.

Is Mallory 9-43155 the same as Sierra 18-3569? Mallory 9-43155 cross-references directly to Sierra 18-3569, so the two part numbers refer to the same thermostat kit application.

How much does the 18-3569 thermostat kit weigh? The Sierra 18-3569 Thermostat Kit weighs 0.08 pounds.

Do I need to buy separate gaskets with this thermostat? No, the 18-3569 kit already includes the 18-0182 thermostat gasket and the 18-0339 thermostat cover gasket along with the thermostat, so no separate gaskets are needed.

Will the 18-3569 kit fit a 4 stroke Mercury outboard? The Sierra 18-3569 Thermostat Kit is designed for Mercury/Mariner 70-125 HP 2 cycle outboards, 1987 and newer, not 4 stroke models.

Does Sierra make this thermostat kit to OEM standards? Sierra manufactures the 18-3569 Thermostat Kit to meet or exceed the specifications of the original equipment part it replaces.

What is the UPC for the Sierra 18-3569 Thermostat Kit? The UPC for the Sierra 18-3569 Thermostat Kit is 808282112899.