{"product_id":"mercury-mercruiser-o-ring-25-54029","title":"Mercury MerCruiser Quicksilver O-Ring 25-54029 (2.800\" × .103\")","description":"\u003ch2\u003eMercury Quicksilver O-Ring 25-54029 – 2.800” × .103”\u003c\/h2\u003e\n\n\u003cp\u003eThis is a genuine OEM Mercury Marine \/ Quicksilver O-ring with a 2.800-inch inside diameter and a 0.103-inch cross-section. The larger diameter of this O-ring places it in housings, end caps, and fluid passage fittings found in MerCruiser sterndrive and engine assemblies — positions where a proper seal is critical to preventing coolant, oil, or fuel leaks. Always confirm the correct diagram position using your engine model and serial number before ordering.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003ePart Details\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 25-54029 (also referenced as 54029)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Mercury Marine \/ Quicksilver\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOfficial Product Type:\u003c\/strong\u003e O-Ring \/ Sealing Element\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInside Diameter (ID):\u003c\/strong\u003e 2.800 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCross-Section (CS):\u003c\/strong\u003e 0.103 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSystem:\u003c\/strong\u003e Varies by application — confirm via parts diagram\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e New OEM\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eCompatible Applications\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eMerCruiser sterndrive and inboard engine assemblies — specific position varies by model and serial number range\u003c\/li\u003e\n  \u003cli\u003eCommonly found in housing end caps, fluid passage fittings, and larger-bore sealing positions\u003c\/li\u003e\n  \u003cli\u003eVerify fitment using the Mercury parts diagram, engine model, and serial number before ordering\u003c\/li\u003e\n  \u003cli\u003eThe 2.800” ID distinguishes this from smaller-bore O-rings in the same assembly — do not substitute by size alone\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDimensions\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInside Diameter:\u003c\/strong\u003e 2.800 in (71.12 mm)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCross-Section:\u003c\/strong\u003e 0.103 in (2.62 mm)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApproximate weight:\u003c\/strong\u003e 10 g (0.01 kg)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eClean the O-ring groove and mating surfaces thoroughly before installation\u003c\/li\u003e\n  \u003cli\u003eLightly lubricate with the appropriate fluid or O-ring lubricant — do not use petroleum-based grease on fuel-system O-rings\u003c\/li\u003e\n  \u003cli\u003eSeat evenly in the groove — do not twist or stretch during installation\u003c\/li\u003e\n  \u003cli\u003eReplace all O-rings disturbed during disassembly; do not reuse compressed or hardened seals\u003c\/li\u003e\n  \u003cli\u003eFollow the Mercury service manual for torque specifications on associated fasteners\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eService Interval\u003c\/h2\u003e\n\u003cp\u003eReplace whenever the assembly is disassembled, when leakage is detected at the sealing surface, or when the O-ring shows visible compression set, cracking, or hardening. Mercury service procedures typically specify replacing all O-rings as a matter of course during overhaul.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eParts Desk Insights\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eBest use case:\u003c\/strong\u003e Resealing larger housing bores, end caps, and fluid passage fittings during overhaul or targeted leak repair. The 2.800” ID is a relatively large O-ring in the Mercury catalog, which helps narrow down the assembly location — if you’re working on a smaller fitting and this seems too large, double-check the diagram position number.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon mistakes:\u003c\/strong\u003e Substituting by cross-section size alone without confirming the inside diameter — an O-ring that is too small in ID will be over-stretched and fail prematurely, while one that is too large will not seat properly. Also confirm the O-ring material is appropriate for the fluid being sealed: Mercury uses different compounds for fuel, coolant, and oil applications, and they are not interchangeable even when dimensions match.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eRelated Parts\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/mercury-mercruiser-o-ring-25-53421\"\u003eMercury MerCruiser Quicksilver O-Ring 25-53421\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/mercury-mercruiser-quicksilver-o-ring-20826\"\u003eMercury MerCruiser Quicksilver O-Ring 20826\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/mercury-mercruiser-quicksilver-o-ring-20863\"\u003eMercury MerCruiser Quicksilver O-Ring 20863\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/mercury-mercruiser-quicksilver-o-ring-8m0204645\"\u003eMercury MerCruiser Quicksilver O-Ring 8M0204645\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/mercury-mercruiser-quicksilver-o-ring-23145\"\u003eMercury MerCruiser Quicksilver O-Ring 23145\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/mercury-mercruiser-quicksilver-shift-pin-o-ring-25007\"\u003eMercury MerCruiser Quicksilver Shift Pin O-Ring 25007\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"\/products\/quicksilver-o-ring-26722-mercury-mercruiser-oem\"\u003eQuicksilver O-Ring 26722\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"MERC","offers":[{"title":"Default Title","offer_id":43563862261796,"sku":"54029","price":6.29,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/images-2026-08-20T132720.864.jpg?v=1787259023","url":"https:\/\/marisolmarine.com\/products\/mercury-mercruiser-o-ring-25-54029","provider":"Marisol Marine Company","version":"1.0","type":"link"}