{"product_id":"centek-exhaust-thru-hull-3in-flapper-1200299-black","title":"Centek 3 in. Exhaust Thru-Hull with Flapper 1200299 | Black","description":"\u003ch2\u003eCentek 3 in. Exhaust Thru-Hull with Flapper 1200299\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 1200299 (Centek Marine)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Centek Marine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Marine Exhaust Thru-Hull with Flapper\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Black\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExhaust Hose Size:\u003c\/strong\u003e 3 in. \/ 76 mm ID\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConstruction:\u003c\/strong\u003e Compression-molded fiberglass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808880120470\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eCentek 1200299 is a black compression-molded fiberglass marine exhaust thru-hull fitting for wet-exhaust systems using 3 in. \/ 76 mm inside-diameter exhaust hose. It installs through the transom or hull side at the exhaust discharge point, with the hose connecting to the inside shank and the flange and weighted rubber flapper remaining on the exterior. The external rubber flapper reduces backflow of water through the exhaust outlet when the boat is stopped, reversing, or exposed to following seas.\u003c\/p\u003e\n\n\u003ch2\u003eDimensions\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNominal Outside Diameter (A):\u003c\/strong\u003e 3.00 in. \/ 76 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExternal Projection Length (B):\u003c\/strong\u003e 2.50 in. \/ 64 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length (C):\u003c\/strong\u003e 5.50 in. \/ 140 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlange Diameter (D):\u003c\/strong\u003e 4.88 in. \/ 124 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThru-Hull \/ Shank Length (E):\u003c\/strong\u003e 3.00 in. \/ 76 mm\u003c\/li\u003e\n\u003cli\u003eFour pre-drilled mounting holes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatible Applications\u003c\/h2\u003e\n\u003cp\u003eSuitable for:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMarine wet-exhaust systems requiring a 3 in. \/ 76 mm exhaust hose connection\u003c\/li\u003e\n\u003cli\u003eTransom or hull-side exhaust discharge installations\u003c\/li\u003e\n\u003cli\u003eNew builds and exhaust-system replacements where a 4.88 in. \/ 124 mm exterior flange fits the mounting area\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eConfirm exhaust hose inside diameter, available hull or transom thickness, required flange diameter, and clearance for the external flapper before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eReplacement Flapper\u003c\/h2\u003e\n\u003cp\u003eThe external rubber flapper is serviceable separately. If the thru-hull body remains structurally sound, the flapper can be replaced without replacing the entire fitting using Centek repair kit \u003cstrong\u003e1200313\u003c\/strong\u003e, which includes a black rubber flapper, two mounting screws, and a small retaining plate.\u003c\/p\u003e\n\n\u003ch2\u003eRelated Part Numbers\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCentek:\u003c\/strong\u003e 1200299 (this part — black)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDistributor\/Catalogue Reference:\u003c\/strong\u003e 383-1200299\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhite equivalent:\u003c\/strong\u003e Centek 1200298\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement 3 in. flapper repair kit:\u003c\/strong\u003e Centek 1200313\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWhen to Replace the Thru-Hull\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eFiberglass body is cracked or structurally compromised\u003c\/li\u003e\n\u003cli\u003eHose-connection shank is damaged or deformed\u003c\/li\u003e\n\u003cli\u003eMounting flange or holes are deteriorated\u003c\/li\u003e\n\u003cli\u003eExhaust leakage is visible around the fitting\u003c\/li\u003e\n\u003cli\u003eFitting is being replaced as part of a full exhaust-system rebuild\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eIf only the flapper shows wear, the flapper can be replaced separately using Centek 1200313 — a full thru-hull replacement is not required.\u003c\/p\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eConfirm the hull opening and mounting area suit the 4.88 in. \/ 124 mm exterior flange\u003c\/li\u003e\n\u003cli\u003eEnsure the mating hull or transom surface is clean and flat before fitting\u003c\/li\u003e\n\u003cli\u003eApply a marine-grade sealant around the flange for a watertight installation\u003c\/li\u003e\n\u003cli\u003eUse 3 in. \/ 76 mm ID marine exhaust hose on the interior connection\u003c\/li\u003e\n\u003cli\u003eTighten all mounting hardware evenly — do not overtighten on the fiberglass flange\u003c\/li\u003e\n\u003cli\u003eAvoid excessive hose-clamp pressure on the fiberglass shank\u003c\/li\u003e\n\u003cli\u003eConfirm the flapper opens freely and swings clear of the hull after installation\u003c\/li\u003e\n\u003cli\u003eInspect for exhaust and cooling-water leaks after startup\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eParts Desk Insights\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eBest use case:\u003c\/strong\u003e Centek 1200299 is the go-to transom exhaust outlet for any wet-exhaust system running 3 in. exhaust hose where a fiberglass fitting is preferred over a metallic one. The compression-molded fiberglass body resists the corrosion that affects metallic exhaust fittings in marine service, and the weighted external flapper is effective at reducing water ingestion when the boat is stopped or backing down. It’s also an ideal choice for a direct replacement on any boat already fitted with a Centek thru-hull in this size.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon issue:\u003c\/strong\u003e The most frequent ordering mistake is not verifying the flange diameter before purchasing. At 4.88 in. \/ 124 mm, the exterior flange is larger than the 3 in. hose opening, so the available mounting area on the transom or hull side needs to be confirmed. Customers also sometimes replace the entire thru-hull when only the rubber flapper has failed — the Centek 1200313 flapper repair kit is the more economical fix when the fiberglass body is still sound.\u003c\/p\u003e\n\u003cp\u003eShop all exhaust components in our \u003ca href=\"\/collections\/exhaust-systems\"\u003eExhaust Systems\u003c\/a\u003e collection or browse \u003ca href=\"\/collections\/engine-parts-maintenance\"\u003eEngine Parts \u0026amp; Maintenance\u003c\/a\u003e for related components.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51156127318052,"sku":"383-1200299","price":208.29,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/383-1200301_78fddbef-2a57-4a2c-826a-99890409d3a9.jpg?v=1784926261","url":"https:\/\/marisolmarine.com\/products\/centek-exhaust-thru-hull-3in-flapper-1200299-black","provider":"Marisol Marine Company","version":"1.0","type":"link"}