{"product_id":"thermostat-fits-mercury-marine-75-175-hp-dfi-replaces-833072-833072002-833072003-833072004","title":"Thermostat – Fits Mercury Marine 75-175 HP DFI (Replaces 833072, 833072002, 833072003, 833072004)","description":"\u003csection\u003e\n\u003c!-- 🔧 Table Styles (include only once per page) --\u003e\n\u003cstyle\u003e\n  \/* Outer container allows horizontal scrolling (with iOS momentum) *\/\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n\n  \/* Base table styles *\/\n  table.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\n  table.ss-table th, table.ss-table td {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n\n  \/* Key: prevent wrapping, word breaks, and vertical text in headers *\/\n  table.ss-table th {\n    white-space:nowrap;       \/* Do not wrap *\/\n    word-break:normal;        \/* Don’t break words *\/\n    letter-spacing:normal;    \/* Prevent theme styles from stretching letters *\/\n    font-weight:600;\n    background:#f8fafc;\n  }\n\n  \/* Small screen optimization *\/\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003eThermostat – Fits Mercury Marine 75-175 HP DFI Outboard Motors (Replaces 833072, 833072002, 833072003, 833072004)\u003c\/strong\u003e is designed for a wide range of Mercury Marine DFI 2-Stroke outboards from 1998 and newer. It is compatible with 1.5L 3-cylinder engines (75-115 HP) and 2.5L V6 engines (135-175 HP).\u003c\/p\u003e\n\u003cp\u003eThis component serves as a direct interchange for Mercury part numbers 833072, 833072002, 833072003, 833072004, and Sierra 18-3536.\u003c\/p\u003e\n\u003cul\u003e\n    \u003cli\u003eInstalls as a direct replacement for the original part.\u003c\/li\u003e\n    \u003cli\u003eRegulates engine temperature at a consistent 143°F (61.6°C).\u003c\/li\u003e\n    \u003cli\u003eRequires thermostat seal 27-887978 for installation (sold separately).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003ePart Number\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e833072\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e833072002\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e833072004\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3536\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n\u003cp\u003eThis thermostat fits specific Mercury Marine DFI and Optimax outboard models. Please verify your engine's serial number range for an exact match.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine \u0026amp; Model Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel\u003c\/th\u003e\n        \u003cth\u003eRated HP\u003c\/th\u003e\n        \u003cth\u003eStroke\u003c\/th\u003e\n        \u003cth\u003eYears\u003c\/th\u003e\n        \u003cth\u003eOEM Part No.\u003c\/th\u003e\n        \u003cth\u003eNotes\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e1.5L 3-Cyl DFI\u003c\/td\u003e\n        \u003ctd\u003e75\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2006–Up (0T980000-Up)\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e1.5L 3-Cyl DFI\u003c\/td\u003e\n        \u003ctd\u003e90\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Up (0T801000-Up)\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e1.5L 3-Cyl DFI\u003c\/td\u003e\n        \u003ctd\u003e115\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Up (0T801000-Up)\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e2.5L V135 DFI\u003c\/td\u003e\n        \u003ctd\u003e135\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1998–Up (0G590000-Up)\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e2.5L V150 DFI\u003c\/td\u003e\n        \u003ctd\u003e150\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1998–Up (0G590000-Up)\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e2.5L V175 DFI\u003c\/td\u003e\n        \u003ctd\u003e175\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2001–Up (0T178500-Up)\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eOptimax\u003c\/td\u003e\n        \u003ctd\u003e135-200\u003c\/td\u003e\n        \u003ctd\u003e2-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1998–Up\u003c\/td\u003e\n        \u003ctd\u003e833072003\u003c\/td\u003e\n        \u003ctd\u003e\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n\u003cdd\u003eEngine Thermostat\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect Replacement\u003c\/dd\u003e\n  \u003cdt\u003eHousing Color\u003c\/dt\u003e\n\u003cdd\u003eSilver\/Metallic\u003c\/dd\u003e\n  \u003cdt\u003eOperating Temperature\u003c\/dt\u003e\n\u003cdd\u003e143°F (61.6°C)\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eRequires thermostat seal 27-887978 (not included)\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n    \u003cli\u003e1 x Thermostat (833072\/833072002\/833072003\/833072004)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n    \u003cli\u003eDisconnect the battery before beginning work.\u003c\/li\u003e\n    \u003cli\u003eAllow the engine to cool completely and drain the cooling system.\u003c\/li\u003e\n    \u003cli\u003eLocate the thermostat housing on the engine block.\u003c\/li\u003e\n    \u003cli\u003eRemove the bolts securing the housing cover.\u003c\/li\u003e\n    \u003cli\u003eRemove the old thermostat and its seal. Note the orientation of the thermostat.\u003c\/li\u003e\n    \u003cli\u003eThoroughly clean the mating surfaces of the housing and cover.\u003c\/li\u003e\n    \u003cli\u003eInstall the new thermostat in the correct orientation.\u003c\/li\u003e\n    \u003cli\u003eInstall a new thermostat seal (part no. 27-887978, sold separately).\u003c\/li\u003e\n    \u003cli\u003eReinstall the housing cover and tighten bolts to the manufacturer's specified torque.\u003c\/li\u003e\n    \u003cli\u003eRefill the cooling system with the appropriate coolant.\u003c\/li\u003e\n    \u003cli\u003eReconnect the battery, start the engine, and check for leaks as it comes up to temperature.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eHow do I know if my thermostat has failed?\u003c\/summary\u003e\n    \u003cp\u003eCommon signs of a faulty thermostat include the engine overheating at various speeds, running too cold (not reaching operating temperature), or erratic temperature gauge readings. A stuck-open thermostat will prevent the engine from warming up, while a stuck-closed one will cause rapid overheating.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eIs the thermostat seal included?\u003c\/summary\u003e\n    \u003cp\u003eNo, the required thermostat seal (Mercury part number 27-887978) is not included with this thermostat and must be purchased separately to ensure a proper, leak-free installation.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eWill this fit my Optimax engine?\u003c\/summary\u003e\n    \u003cp\u003eThis thermostat fits many Mercury Optimax models from 135 to 200 HP, manufactured from 1998 onwards. However, it is critical to consult your engine’s service manual or verify the OEM part number for your specific model and serial number to guarantee compatibility.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eWhat is the correct operating temperature?\u003c\/summary\u003e\n    \u003cp\u003eThis thermostat is designed to open at 143°F (61.6°C), allowing coolant to circulate and maintain the engine within its optimal temperature range for performance and efficiency.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eHow often should I replace an outboard thermostat?\u003c\/summary\u003e\n    \u003cp\u003eFor preventative maintenance, it is good practice to inspect the thermostat annually and consider replacement every 2-3 years, or as recommended by your engine's manufacturer. Replacement is especially important if the boat is used in saltwater environments, which can accelerate corrosion.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eOEM vs. Aftermarket?\u003c\/summary\u003e\n    \u003cp\u003eThis listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eShipping speed \u0026amp; cost?\u003c\/summary\u003e\n    \u003cp\u003eWe ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n    \u003csummary\u003eWarranty \u0026amp; returns?\u003c\/summary\u003e\n    \u003cp\u003eCovered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused \u0026amp; in original condition). See our policy page or reach out for instructions.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n    \u003cli\u003eVerify images\/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.\u003c\/li\u003e\n    \u003cli\u003eThis is an aftermarket replacement, not an OEM component.\u003c\/li\u003e\n    \u003cli\u003eProfessional installation is recommended for safety and performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePro-Grade Standards\u003c\/strong\u003e — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eFast Global Fulfillment\u003c\/strong\u003e — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — Fair pricing without compromising on materials or QC.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50718262690107,"sku":"833072002-QM","price":19.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/833072002-QM.png?v=1762958391","url":"https:\/\/seasierra.com\/products\/thermostat-fits-mercury-marine-75-175-hp-dfi-replaces-833072-833072002-833072003-833072004","provider":"SeaSierra","version":"1.0","type":"link"}