{"product_id":"mercury-w-a-thermostat-j-e-435491-8m6010305","title":"Mercury – 143° Thermostat | Cooling System Components | Precision Brass | 8M6010305","description":"\u003ch3\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eMercury – 143° Thermostat | Cooling System Components | Precision Brass | 8M6010305\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h3\u003e\n\u003ch2\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eOverview\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eEvery outboard has its own personality, but one thing they all share is the need for steady, predictable cooling—especially the hardworking two-strokes that many of us grew up trusting. The Quicksilver 8M6010305 143-degree thermostat steps into that role with the kind of quiet reliability that makes long runs feel effortless. When the water’s glassy and the engine settles into that familiar hum, you want to know the temperature inside the block is staying exactly where it should. That sense of confidence—of knowing your motor is protected and performing at its best—is what this thermostat delivers.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eKey Features\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eMaintains optimal 143°F operating temperature for select 90–170hp Evinrude, Johnson, and OMC two-stroke outboards\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eDesigned to meet or exceed all original factory specifications\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan data-preserver-spaces=\"true\"\u003eDir\u003c\/span\u003e\u003cspan data-preserver-spaces=\"true\"\u003eect replacement for OEM part number 435491 and compatible with additional cross-references\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eDurable, marine-grade construction engineered for consistent thermal response\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eThermostat only; installation hardware and gaskets sold separately\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eSimple replacement process following standard service-manual guidance\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eEngine \u0026amp; Boat Compatibility\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan data-preserver-spaces=\"true\"\u003eFit\u003c\/span\u003e\u003cspan data-preserver-spaces=\"true\"\u003es select 90–170hp Evinrude, Johnson, and OMC V4 and V6 two-stroke outboards\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eSuitable for classic fishing rigs, lightweight skiffs, mid-size offshore hulls, and restored two-stroke setups\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eIdeal for engines used frequently in mixed-water environments such as brackish estuaries, inland rivers, and coastal runs\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan data-preserver-spaces=\"true\"\u003eDes\u003c\/span\u003e\u003cspan data-preserver-spaces=\"true\"\u003eigned for motors that rely on precise temperature regulation for fuel economy, throttle response, and smooth idle\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003ePerformance \u0026amp; Practical Benefits\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eA thermostat may be small, but any boater who’s ever fought overheating or sluggish warm-ups knows just how big of a difference it makes. Thi\u003c\/span\u003e\u003cspan data-preserver-spaces=\"true\"\u003es Quicksilver thermostat delivers a steady, predictable temperature curve, helping your two-stroke get up to operating temp quickly and hold it without drifting. The result? Smoother starts on cool mornings, more responsive throttle transitions, and a cleaner-burning engine that doesn’t waste fuel trying to compensate for temperature swings.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eIts\u003c\/span\u003e\u003cspan data-preserver-spaces=\"true\"\u003e tight, secure fit keeps water flowing exactly as the engineers intended. You’ll notice steadier running at idle, a more confident transition to plane, and better overall efficiency on long cruising stretches. And because the thermostat’s design matches OEM specs down to the smallest detail, there’s no guesswork—just a part that drops in and behaves exactly the way your engine expects.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eWhy Buy OEM\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eWhen it comes to cooling, precision matters. Aftermarket thermostats may run “close enough,” but close isn’t good enough when you’re miles from shore or trying to keep an older two-stroke running strong season after season. A genuine Quicksilver part gives you the correct temperature rating, correct dimensions, and the peace of mind that comes from using something engineered for long-term dependability. It’s the practical choice—not flashy, not complicated, just right.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eFAQ\u003c\/span\u003e\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ1: Which Mercury engines or systems does this thermostat fit?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e This part is for select 90–170hp Evinrude, Johnson, and OMC V4 and V6 outboards—confirm fit using your engine’s model and serial number.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ2: What makes this part different from aftermarket options?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e It’s built to exact OEM specifications, ensuring proper thermal control and long-term reliability.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ3: How do I know if it’s the correct replacement?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e Match the part number (435491 replacement) and verify compatibility through your owner’s manual.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ4: Can it be used in saltwater and freshwater?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e Yes—this thermostat performs reliably in all marine environments.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ5: Is installation straightforward?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e Most boaters with basic mechanical comfort can handle the swap by following the service manual.\u003c\/span\u003e\u003c\/p\u003e","brand":"Mercury","offers":[{"title":"Default Title","offer_id":46935057531171,"sku":"8M6010305","price":27.08,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0783\/7410\/9475\/files\/8M6010305_Main.jpg?v=1760631532","url":"https:\/\/partsvu.com\/en-ca\/products\/mercury-w-a-thermostat-j-e-435491-8m6010305","provider":"PartsVu","version":"1.0","type":"link"}