{"product_id":"yiuiy-thermostat-for-yamaha-2-stroke-outboards-3hp-250hp-2-piece-copper-replacement-direct-fit","title":"YIUIY Thermostat for Yamaha 2-Stroke Outboards 3HP-250HP — 2-Piece Copper Replacement, Direct-Fit","description":"\u003cp\u003e\u003cstrong\u003eYIUIY thermostats are replacement cooling valves engineered to restore correct engine operating temperature in Yamaha 2-stroke outboards from 3HP up to 250HP (sold as a 2-piece set).\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eWhen an outboard thermostat fails it can cause inconsistent temperatures and reduced engine performance. This pair of YIUIY thermostats fits a broad range of Yamaha 2-stroke models and replaces many common factory part numbers, offering a durable copper construction and direct-fit design to simplify installation and get your boat back on the water faster.\u003c\/p\u003e\n\n\u003ch3\u003eWhat models and part numbers does this thermostat replace?\u003c\/h3\u003e\n\u003cp\u003eThese thermostats cover most Yamaha 2-stroke outboards across small to large horsepower ranges. They are designed to be compatible with numerous OEM references so you can match the replacement easily.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible horsepower: 3HP to 250HP, including 6HP, 9.9HP, 25HP, 90HP, 150HP, 200HP, and others.\u003c\/li\u003e\n  \u003cli\u003eReplaces popular part numbers such as 688-12411-10-00, 6E5-12411-30-00, 6H3-12411-11-00, 6E5-12411-02-00, and more.\u003c\/li\u003e\n  \u003cli\u003eSold as a 2-piece set to service multiple outlets or to keep a spare on board.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does this thermostat affect engine temperature and performance?\u003c\/h3\u003e\n\u003cp\u003eThe thermostat controls coolant flow so the engine reaches and stays within its optimal temperature range. Proper thermostat function prevents the engine from running too cool, which can harm efficiency and increase wear over time.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eOpens and closes to regulate coolant circulation through the engine block and water jacket.\u003c\/li\u003e\n  \u003cli\u003eHelps maintain stable operating temperature for better fuel efficiency and combustion.\u003c\/li\u003e\n  \u003cli\u003ePrevents chronic under-temperature conditions that can reduce power and increase component stress.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat materials and build quality can I expect from the YIUIY unit?\u003c\/h3\u003e\n\u003cp\u003eYIUIY thermostats are manufactured from copper alloy components that match the form and function of factory parts. The choice of materials and adherence to original design dimensions aim to provide reliable service life and straightforward replacement.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCopper-based construction for corrosion resistance and reliable thermal response.\u003c\/li\u003e\n  \u003cli\u003eDesigned to meet OEM geometry for direct fit and easy installation.\u003c\/li\u003e\n  \u003cli\u003eDurability suited for saltwater and freshwater environments when installed correctly.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I confirm fitment and install the replacement thermostat?\u003c\/h3\u003e\n\u003cp\u003eConfirm the correct part by comparing your engine’s current thermostat part number with the replacement list. Installation typically involves removing the thermostat housing, swapping the unit, and reassembling with proper seals—no special tools usually required.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCheck existing part numbers before purchase to ensure compatibility.\u003c\/li\u003e\n  \u003cli\u003eFollow Yamaha service guidelines for thermostat removal and installation.\u003c\/li\u003e\n  \u003cli\u003eInspect gaskets and hoses while the housing is open and replace if worn.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Boaters, marine technicians, and DIY enthusiasts who own Yamaha 2-stroke outboards and need a cost-effective, OEM-form replacement thermostat. Ideal for routine maintenance, preventative parts stocking, or swapping a failed thermostat to restore proper engine temperature control. If you’re unsure about fitment, inspect the part number on your engine or contact YIUIY customer support for help before ordering.\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: Will this thermostat fit my Yamaha outboard?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Compare your engine’s existing part number with the replacement list; it fits many 2-stroke Yamaha models 3HP–250HP.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Are these thermostats ready to install as-is?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. They are direct-fit replacements, but check gaskets and follow Yamaha installation steps for proper sealing.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"YIUIY","offers":[{"title":"Default Title","offer_id":48084450607262,"sku":"B09TT3R8DN","price":31.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/yiuiy-thermostat-front-view.jpg?v=1785855756","url":"https:\/\/northtrailauto.ca\/products\/yiuiy-thermostat-for-yamaha-2-stroke-outboards-3hp-250hp-2-piece-copper-replacement-direct-fit","provider":"North Trail Auto","version":"1.0","type":"link"}