{"product_id":"hei-ignition-coil-for-mercruiser-thunderbolt-iv-v-392-7803a4-392-805570a2","title":"HEI Ignition Coil for MerCruiser Thunderbolt IV V 392-7803A4 392-805570A2","description":"\u003cstrong\u003eThis HEI Ignition Coil is a high-energy ignition component compatible with MerCruiser Thunderbolt IV and V marine engines and matches OEM Part# 392-7803A4 and 392-805570A2.\u003c\/strong\u003e\u003ch2\u003eProduct Overview\u003c\/h2\u003e\u003ch3\u003eKey Features \u0026amp; Performance\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eHigh Energy Ignition (HEI) design delivers a powerful spark for improved combustion\u003c\/li\u003e\n\u003cli\u003eDirect replacement for MerCruiser Thunderbolt IV and V ignition systems\u003c\/li\u003e\n\u003cli\u003eEpoxy-filled construction resists vibration and moisture common in marine environments\u003c\/li\u003e\n\u003cli\u003eIncludes mounting bracket and hardware for straightforward installation\u003c\/li\u003e\n\u003cli\u003eMeets or exceeds OEM specifications for reliable engine starts and smooth idle\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment \u0026amp; Compatibility\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMerCruiser Thunderbolt IV ignition systems\u003c\/li\u003e\n\u003cli\u003eMerCruiser Thunderbolt V ignition systems\u003c\/li\u003e\n\u003cli\u003eReplaces OEM part numbers 392-7803A4 and 392-805570A2\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eCommon Uses\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eReplacing faulty or worn ignition coils on inboard and sterndrive MerCruiser engines\u003c\/li\u003e\n\u003cli\u003eRestoring spark performance on Thunderbolt IV and V equipped marine powerplants\u003c\/li\u003e\n\u003cli\u003eUpgrading from conventional coils to a high-energy design for better reliability\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number(s):\u003c\/strong\u003e 392-7803A4, 392-805570A2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e HEI Ignition Coil\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrimary Resistance:\u003c\/strong\u003e 0.5–1.5 ohms\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSecondary Resistance:\u003c\/strong\u003e 8–12 k ohms\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eQ:\u003c\/strong\u003e Will this coil work on a standard MerCruiser distributor?\u003cstrong\u003e A:\u003c\/strong\u003e Yes, it is designed for Thunderbolt IV and V distributors but may fit other models if the mounting pattern and electrical specs match.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ:\u003c\/strong\u003e Do I need to replace the spark plug wires at the same time?\u003cstrong\u003e A:\u003c\/strong\u003e It is recommended to inspect your wires; HEI coils produce higher voltage and worn wires may cause misfire.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eProduct appearance and specifications may vary slightly by batch. Compatibility may vary by serial number. Verify fitment before purchase.\u003c\/em\u003e\u003c\/p\u003e","brand":"DURAFORCE","offers":[{"title":"Default Title","offer_id":53676785893649,"sku":"ZZ2Y01634","price":76.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0250\/2446\/2929\/files\/57_837b12b6-98c8-4cda-b679-90e9a8a67e2b.jpg?v=1781578249","url":"https:\/\/www.duraforce.com\/products\/hei-ignition-coil-for-mercruiser-thunderbolt-iv-v-392-7803a4-392-805570a2","provider":"DURAFORCE","version":"1.0","type":"link"}