SIERRA 118-3622 Cooling Water Thermostat

Compatible Engines

The SIERRA 118-3622 cooling water thermostat is a critical component of the cooling system, ensuring optimal operating temperature for your power unit. It opens at 50 °C (122 °F), which is standard for many outboard engine designs. Due to the lack of an official catalog list specifying exact engine models compatible with this part, we recommend verifying compatibility. The safest approach is to compare the manufacturer's catalog number 118-3622 with the OE (original) number available in your engine's owner manual. If you have any doubts regarding fitment, contact our store support, and we will help you select the correct part.

Installation and Operation

Proper installation of the thermostat is crucial for engine longevity. Before replacement, ensure the system is completely cooled down and the coolant has been drained. Carefully clean the mounting seat from deposits and corrosion to ensure a tight seal for the new gasket. During installation, pay attention to the thermostat orientation—the arrow on the housing should indicate the direction of fluid flow. After reassembling the system, top up the coolant level and bleed the system to avoid creating "air pockets," which can lead to engine overheating despite the new thermostat.

• Original SIERRA quality – guarantees durability and precise operation in harsh marine conditions.
• 50 °C specification – ensures rapid engine warm-up and maintains optimal operating temperature.
• Easy replacement – standard shape facilitates disassembly and installation without specialized tools.
• Corrosion protection – materials resistant to saltwater and coolant action guarantee a long service life.