{"product_id":"mercury-spark-plug-ac-41-983-fits-mcm-496-mag-ho-and-mie-8-1l-ho-33-8m0129146","title":"Mercury – ACDelco Double Platinum Spark Plug | Ignition System | Nickel Alloy \u0026amp; Copper Core | 8M0129146","description":"\u003ch2\u003e\u003cspan data-preserver-spaces=\"true\"\u003eMercury – ACDelco Double Platinum Spark Plug | Ignition System | Nickel Alloy \u0026amp; Copper Core | 8M0129146\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eOverview\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e There’s a particular kind of comfort that comes from an engine that fires immediately—no hesitation, no uneven rumble, just a clean, confident start that tells you the day’s going to go right. That feeling isn’t accidental. It comes from parts like the Mercury 8M0129146 ACDelco GM Original Equipment Double Platinum Spark Plug doing their job exactly as they should. When you’re pushing a heavy MerCruiser through chop or easing into a tight marina, you want ignition you can trust every single time. This spark plug brings that kind of reliability—quietly, consistently, and without drama.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan data-preserver-spaces=\"true\"\u003eKey Features\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan data-preserver-spaces=\"true\"\u003eD\u003c\/span\u003e\u003cspan data-preserver-spaces=\"true\"\u003eouble platinum spark plug engineered for long-lasting ignition performance\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eNickel alloy tip and copper core construction for stable conductivity\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eRibbed suppressor seal designed to reduce misfires and improve acceleration\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eBuilt to match OEM specifications for MerCruiser 496 Mag, 496 Mag HO, and MIE 8.1L engines\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eDesigned for full replacement rather than cleaning or refurbishing\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\n\u003cspan data-preserver-spaces=\"true\"\u003eE\u003c\/span\u003e\u003cspan data-preserver-spaces=\"true\"\u003engine \u0026amp; Boat Compatibility\u003c\/span\u003e\n\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eFits MerCruiser 496 Mag sterndrive engines\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eFits MerCruiser 496 Mag HO engines\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eFits MerCruiser MIE 8.1L and 8.1L HO inboard engines\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eIdeal for cruisers, sport boats, performance sterndrives, and larger offshore fishing boats\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan data-preserver-spaces=\"true\"\u003ePerformance \u0026amp; Practical Benefits\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eWhen your spark plugs are fresh and properly matched to your engine, everything feels better. The throttle response tightens up. Starts become quick and predictable. And on long runs, you’ll feel the engine settle into that smooth, steady rhythm that only a well-maintained ignition system delivers.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eThe 8M0129146 plug uses a copper core for consistent thermal control, which is crucial in big-block marine engines that run hot under load. The double platinum pads help the plug resist wear over hundreds of hours, delivering crisp ignition even after countless cycles. It’s the kind of part you install once and trust season after season.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eYou’ll also notice fewer small annoyances—reduced sputtering, cleaner idle, and better fuel burn. Big displacement engines rely heavily on spark quality, and a tired plug can steal power without you immediately realizing it. With this Mercury Marine part, the difference feels real: cleaner combustion, steadier pull, and reliable performance whether you’re cruising at low speed or climbing onto plane.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan data-preserver-spaces=\"true\"\u003eWhy Buy OEM\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eIgnition isn’t a place to gamble. Mercury’s OEM spark plugs are built to match the engine’s heat range, firing demands, and design tolerances precisely. Aftermarket options may look similar, but differences in resistance, tip material, or heat control can cause fouling, rough idle, or even long-term engine damage.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eChoosing the genuine ACDelco\/Mercury plug gives you:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eThe correct heat range for your specific block\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eMaximum durability under marine load\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eFactory-level performance and efficiency\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan data-preserver-spaces=\"true\"\u003eA simple, stress-free replacement process\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003eIf you’re already pulling the cowl or hatch to replace plugs, replacing all of them together ensures even performance across cylinders and prevents chasing issues later.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan data-preserver-spaces=\"true\"\u003eFAQ\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ1: Which Mercury engines does the 8M0129146 spark plug fit?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e It fits MerCruiser 496 Mag, 496 Mag HO, and MIE 8.1L \u0026amp; 8.1L HO engines.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ2: What makes this spark plug better than aftermarket versions?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e It’s built to exact OEM specs with double platinum durability, proper heat range, and materials designed specifically for marine use.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ3: How do I know it’s the right plug for my engine?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e Check your owner’s manual—use only the plug listed by Mercury for your specific model.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan data-preserver-spaces=\"true\"\u003eQ4: Can this plug be used in both saltwater and freshwater environments?\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-preserver-spaces=\"true\"\u003e Yes. The materials and construction are designed to resist marine corrosion and maintain stable performance.\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 boat owners with basic mechanical experience can replace plugs easily. Just replace all plugs at the same time for best results.\u003c\/span\u003e\u003c\/p\u003e","brand":"Mercury","offers":[{"title":"Default Title","offer_id":46932447068451,"sku":"33-8M0129146","price":20.67,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0783\/7410\/9475\/files\/8m0129146_main.jpg?v=1761308172","url":"https:\/\/partsvu.com\/en-ca\/products\/mercury-spark-plug-ac-41-983-fits-mcm-496-mag-ho-and-mie-8-1l-ho-33-8m0129146","provider":"PartsVu","version":"1.0","type":"link"}