{"product_id":"78458a1-exhaust-tube-bellow-fits-mercruiser-r-mr-alpha-one-bravo-i-ii-iii-blackhawk-jlm-marine","title":"78458A1 Exhaust Tube Bellow – Fits MerCruiser R MR Alpha One Bravo I II III Blackhawk","description":"\u003cstyle\u003e\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\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  table.ss-table th {\n    white-space:nowrap;\n    word-break:normal;\n    letter-spacing:normal;\n    font-weight:600;\n    background:#f8fafc;\n  }\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\n\u003cp\u003eThe \u003cstrong\u003e78458A1 Exhaust Tube Bellow\u003c\/strong\u003e is designed for MerCruiser R\/MR\/Alpha One (serial no. 6225577 \u0026amp; up, 1983–1990), Bravo I, II, III (serial no. OB664190 \u0026amp; up, 1988 and later), and Blackhawk (serial no. 0F18677 \u0026amp; up, 1994–1995) sterndrive applications. This exhaust bellow connects the exhaust system components while allowing flexibility during engine movement.\u003c\/p\u003e\n\n\u003cp\u003eThis part directly replaces MerCruiser 78458A1, Sierra 18-2760, Mallory 9-72810, and GLM 89150.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eIncludes stainless steel clamp for secure installation\u003c\/li\u003e\n  \u003cli\u003eEngineered to meet or exceed OEM specifications\u003c\/li\u003e\n  \u003cli\u003eSuitable for freshwater and saltwater environments\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\n\u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket.\u003c\/p\u003e\n\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\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003e78458A1\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-2760\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMallory\u003c\/td\u003e\n        \u003ctd\u003e9-72810\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGLM\u003c\/td\u003e\n        \u003ctd\u003e89150\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\n\u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n\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\u003eSerial Number\u003c\/th\u003e\n        \u003cth\u003eYears\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003eR\/MR\/Alpha One\u003c\/td\u003e\n        \u003ctd\u003e6225577 \u0026amp; UP\u003c\/td\u003e\n        \u003ctd\u003e1983–1990\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003eBravo I, II, III\u003c\/td\u003e\n        \u003ctd\u003eOB664190 \u0026amp; UP\u003c\/td\u003e\n        \u003ctd\u003e1988 and later\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003eBlackhawk\u003c\/td\u003e\n        \u003ctd\u003e0F18677 \u0026amp; UP\u003c\/td\u003e\n        \u003ctd\u003e1994–1995\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\n\u003cdl\u003e\n  \u003cdt\u003ePart Type\u003c\/dt\u003e\n  \u003cdd\u003eExhaust Tube Bellow\u003c\/dd\u003e\n  \u003cdt\u003eOEM Reference\u003c\/dt\u003e\n  \u003cdd\u003e78458A1\u003c\/dd\u003e\n  \u003cdt\u003eMaterial\u003c\/dt\u003e\n  \u003cdd\u003eRubber with reinforced construction\u003c\/dd\u003e\n  \u003cdt\u003eClamp Included\u003c\/dt\u003e\n  \u003cdd\u003eStainless steel\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003eMerCruiser Sterndrive Exhaust System\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\u003cstrong\u003e1 × Exhaust Tube Bellow (78458A1)\u003c\/strong\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003cstrong\u003e1 × Stainless Steel Clamp\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\n\u003col\u003e\n  \u003cli\u003eDisconnect battery and ensure engine is cool before starting work.\u003c\/li\u003e\n  \u003cli\u003eRemove outdated or damaged exhaust bellow by loosening the existing clamps.\u003c\/li\u003e\n  \u003cli\u003eInspect mating surfaces on exhaust components for corrosion, cracks, or debris. Clean thoroughly.\u003c\/li\u003e\n  \u003cli\u003eSlide new exhaust bellow onto the exhaust tube, ensuring proper alignment with both connection points.\u003c\/li\u003e\n  \u003cli\u003ePosition the stainless steel clamp over the bellow ends and tighten securely without over-torquing.\u003c\/li\u003e\n  \u003cli\u003eCheck for full seating and confirm no gaps or misalignment exist.\u003c\/li\u003e\n  \u003cli\u003eReconnect battery and run engine briefly to verify proper exhaust flow and seal integrity.\u003c\/li\u003e\n  \u003cli\u003eInspect for leaks or unusual exhaust noise; re-tighten clamps if necessary.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I know if my exhaust bellow needs replacement?\u003c\/summary\u003e\n  \u003cp\u003eLook for visible cracks, tears, or brittleness in the rubber material. Exhaust leaks, unusual exhaust odor in the bilge, or water intrusion near the exhaust area are common signs of failure.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n  \u003csummary\u003eWill this fit my MerCruiser Alpha One Gen II?\u003c\/summary\u003e\n  \u003cp\u003eYes, this exhaust bellow is compatible with MerCruiser Alpha One Gen II drives with serial numbers 6225577 and up (1983–1990). Always verify your serial number before ordering.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n  \u003csummary\u003eCan I reuse the old clamp?\u003c\/summary\u003e\n  \u003cp\u003eIt is not recommended. This kit includes a new stainless steel clamp designed to provide proper tension and corrosion resistance. Reusing old clamps may compromise seal integrity.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n  \u003csummary\u003eWhat tools are required for installation?\u003c\/summary\u003e\n  \u003cp\u003eYou will typically need a socket set or wrenches to loosen and tighten hose clamps, a flathead or nut driver for clamp adjustment, and basic hand tools for accessing the exhaust assembly.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n  \u003csummary\u003eIs this bellow suitable for saltwater use?\u003c\/summary\u003e\n  \u003cp\u003eYes, the exhaust bellow is constructed from durable rubber and includes a stainless steel clamp, making it suitable for both freshwater and saltwater marine environments.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should the exhaust bellow be inspected?\u003c\/summary\u003e\n  \u003cp\u003eInspect the bellow at least once per season or every 100 hours of operation. Replace immediately if cracks, splits, or softening are detected to avoid exhaust leaks and water damage.\u003c\/p\u003e\n\u003c\/details\u003e\n\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\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\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\n\u003cul\u003e\n  \u003cli\u003eVerify images\/specifications against 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\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","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":51024937648443,"sku":"17B1015","price":25.09,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/12.jpg?v=1772886815","url":"https:\/\/seasierra.com\/products\/78458a1-exhaust-tube-bellow-fits-mercruiser-r-mr-alpha-one-bravo-i-ii-iii-blackhawk-jlm-marine","provider":"SeaSierra","version":"1.0","type":"link"}