{"product_id":"great-lakes-memories-thermostat-kit-for-mercury-mercruiser-2-5l-3-0l-140-f-replacement-with-gasket","title":"Great Lakes Memories Thermostat Kit for Mercury Mercruiser 2.5L\/3.0L — 140°F Replacement with Gasket","description":"\u003cp\u003e\u003cstrong\u003eGreat Lakes Memories thermostat kit is a complete replacement thermostat and gasket set engineered to restore correct operating temperature on Mercury Mercruiser 2.5L and 3.0L inline engines.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis replacement kit is designed for small Mercruiser four-cylinder marine engines and fits many inline-six applications as well. It includes a 140°F thermostat and a sealing gasket manufactured to meet or exceed original equipment specifications, making it a direct swap for part numbers 59078, 59078Q3 and 18-3650. The kit is intended to help the engine warm up predictably and maintain stable cooling system performance when installed according to manufacturer service guidance.\u003c\/p\u003e\n\n\u003ch3\u003eWill this thermostat kit fit my Mercruiser 2.5 or 3.0 engine?\u003c\/h3\u003e\n\u003cp\u003eYes — the kit was developed as a direct replacement for common Mercury Mercruiser inline 2.5L and 3.0L four-cylinder units and is compatible with many inline-six applications that use the same thermostat specification. Verify fitment by comparing part numbers and the thermostat housing design before ordering.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReplaces OEM part numbers 59078, 59078Q3, and 18-3650\u003c\/li\u003e\n  \u003cli\u003eIntended for Mercruiser 2.5L and 3.0L inline engines\u003c\/li\u003e\n  \u003cli\u003eAlso compatible with several inline-six engine models using the same thermostat size\u003c\/li\u003e\n  \u003cli\u003eConfirm housing and bolt pattern to ensure proper fit\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat temperature does the thermostat open, and why does that matter?\u003c\/h3\u003e\n\u003cp\u003eThe thermostat in this kit is a 140°F (approximately 60°C) unit, chosen to match factory operating ranges for the specified engines. A thermostat opening at the correct temperature helps the engine reach operating range quickly and keeps coolant flow regulated once warmed, supporting consistent engine performance and emissions behavior.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e140°F rated opening temperature for predictable warm-up\u003c\/li\u003e\n  \u003cli\u003eMaintains stable coolant circulation after warm-up\u003c\/li\u003e\n  \u003cli\u003eHelps protect against overcooling or premature warm-up issues\u003c\/li\u003e\n  \u003cli\u003eMeets or exceeds OEM thermostatic performance specifications\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat comes in the kit and how does it simplify installation?\u003c\/h3\u003e\n\u003cp\u003eThe package contains a 140°F thermostat and a matching gasket, providing the essential components needed for a typical thermostat replacement service. Including the correct gasket reduces the chance of leaks and saves you from sourcing separate sealing parts, streamlining the maintenance task.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOne 140°F thermostat sized for Mercruiser inline engines\u003c\/li\u003e\n  \u003cli\u003eOne matching gasket to ensure a proper seal\u003c\/li\u003e\n  \u003cli\u003eSold as a single kit for immediate replacement use\u003c\/li\u003e\n  \u003cli\u003eDesigned to meet OEM fit and function for straightforward swap-in\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for? This thermostat kit is built for marine owners, DIY mechanics, and professional technicians working on Mercury Mercruiser 2.5L or 3.0L inline engines who need a reliable OEM-replacement thermostat and gasket. It’s aimed at anyone replacing a failed thermostat, correcting irregular engine temperatures, or performing scheduled cooling-system maintenance who requires parts that match original specifications and simplify installation.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this kit replace part number 59078?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. This Great Lakes Memories kit replaces 59078, 59078Q3 and 18-3650 for Mercruiser 2.5\/3.0 engines.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is the thermostat temperature 140°F?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The included thermostat is rated to open at 140°F for proper engine warm-up.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Great Lakes Memories","offers":[{"title":"Default Title","offer_id":48084860108958,"sku":"B07S2L7BDQ","price":40.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/great-lakes-memories-thermostat-kit-front-view.jpg?v=1785864144","url":"https:\/\/northtrailauto.ca\/products\/great-lakes-memories-thermostat-kit-for-mercury-mercruiser-2-5l-3-0l-140-f-replacement-with-gasket","provider":"North Trail Auto","version":"1.0","type":"link"}