Quicksilver Thermostat (140°F MerCruiser 120, 140 & 165 Engines) 59078

The Quicksilver Thermostat (140°F MerCruiser 120, 140 & 165 Engines) 59078 is a genuine Quicksilver OEM replacement thermostat designed to help maintain proper operating temperature for select MerCruiser sterndrive and inboard engines.

Compatible With:

• MerCruiser 120HP 2.5L engines (serial number 2324347 and newer) with cast iron exhaust manifolds
• MerCruiser 140HP 3.0L engines (serial number 0L340999 and earlier)
• MerCruiser 165HP engines

This 140°F thermostat regulates coolant flow through the engine to help maintain the proper operating temperature for optimal performance, fuel efficiency, and engine longevity. A properly functioning thermostat helps the engine warm up quickly while preventing overheating during operation.

Routine thermostat replacement is recommended when servicing the cooling system or if engine temperature becomes inconsistent. Installation can typically be completed using common hand tools. Refer to your owner's or service manual for proper replacement procedures.

Genuine Quicksilver service parts are engineered and tested to Mercury Marine specifications to provide dependable performance, proper fitment, and long service life.

To confirm compatibility, contact our team with your engine serial number at (727) 596-5929 before ordering.