{"product_id":"sierra-18-3687-thermostat-for-suzuki-outboards","title":"Sierra 18-3687 Thermostat for Suzuki Outboard Engines","description":"\u003cp\u003eThe Sierra 18-3687 is a replacement thermostat engineered for Suzuki outboard engines, helping regulate engine coolant temperature so the powerhead runs within its intended operating range. A properly functioning thermostat is a small part with an outsized job: it opens and closes to control coolant flow, preventing the engine from running too cold (which hurts fuel economy and combustion efficiency) or too hot (which risks overheating damage to gaskets, seals, and internal components). This unit is sized for a direct fit in the Suzuki outboard cooling system and is built by Sierra, a long-standing supplier of marine replacement parts trusted for its focus on boat-specific engineering rather than repurposed automotive components.\u003c\/p\u003e\u003cp\u003eAt 2 x 1.2 x 1.9 inches and 0.11 pounds, the 18-3687 is compact and lightweight, consistent with the small in-line thermostats used in outboard cooling circuits. It is intended as a straightforward swap for a worn, stuck, or failed thermostat during routine cooling system maintenance or when troubleshooting overheating or slow warm-up symptoms on a Suzuki outboard.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-3687\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Thermostat\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Suzuki outboard engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 2 x 1.2 x 1.9 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.11 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282383299\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for use in Suzuki outboard engine cooling systems.\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-3687 thermostat fit?\u003c\/strong\u003e The Sierra 18-3687 is designed for use in Suzuki outboard engine cooling systems.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of part number 18-3687?\u003c\/strong\u003e This thermostat measures 2 x 1.2 x 1.9 inches, a compact size typical of in-line outboard thermostats.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-3687 thermostat weigh?\u003c\/strong\u003e It weighs 0.11 pounds, making it a lightweight, easy-to-handle replacement part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-3687 a genuine Sierra part or aftermarket?\u003c\/strong\u003e It is a Sierra-branded thermostat, part number 18-3687, manufactured as a marine replacement part rather than a generic automotive substitute.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does a thermostat do in a Suzuki outboard cooling system?\u003c\/strong\u003e A thermostat opens and closes to regulate coolant flow, keeping the engine within its proper operating temperature range and preventing overheating or excessive cold running.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat symptoms indicate the 18-3687 thermostat needs replacing?\u003c\/strong\u003e Overheating, slow engine warm-up, or fluctuating temperature readings are common signs a Suzuki outboard thermostat like the 18-3687 has failed or is stuck.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when ordering the Sierra 18-3687?\u003c\/strong\u003e The listing includes one Sierra 18-3687 thermostat unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-3687 be installed as a routine maintenance item?\u003c\/strong\u003e Yes, replacing the thermostat during scheduled cooling system maintenance on a Suzuki outboard is a common preventive step.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs professional installation required for the Sierra 18-3687?\u003c\/strong\u003e Thermostat replacement on a Suzuki outboard, including installing part 18-3687, is typically done by a marine technician or an experienced DIY owner familiar with the engine's cooling housing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-3687 come with a gasket?\u003c\/strong\u003e The dossier for the 18-3687 covers the thermostat itself; buyers should confirm gasket needs separately when servicing the cooling system.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988157771995,"sku":"SIE-18-3687","price":40.71,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-3687__30061.1739477161.500.750.jpg?v=1785188915","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-3687-thermostat-for-suzuki-outboards","provider":"Good Vibes Marina","version":"1.0","type":"link"}