{"product_id":"mercury-mercruiser-spark-plug-wire-kit-fits-gm-v-8-305-350-cid-engines-with-thunderbolt-iv-ignition-84-816761q4","title":"Mercury – Quicksilver 816761Q4 Spark Plug Wire Kit | V8 GM MerCruiser (LH) Engines (305 \u0026 350 CID) | Thunderbolt IV Ignition | 816761Q4","description":"\u003cp data-start=\"0\" data-end=\"141\"\u003e\u003cstrong data-start=\"0\" data-end=\"139\"\u003eMercury – Quicksilver 816761Q4 Spark Plug Wire Kit | V8 GM MerCruiser (LH) Engines (305 \u0026amp; 350 CID) | Thunderbolt IV Ignition | 816761Q4\u003c\/strong\u003e\u003c\/p\u003e\n\u003chr data-start=\"143\" data-end=\"146\"\u003e\n\u003ch3 data-start=\"148\" data-end=\"166\"\u003e\u003cstrong data-start=\"152\" data-end=\"164\"\u003eOverview\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"167\" data-end=\"446\"\u003eWhen your boat starts instantly and runs smooth, that’s good spark at work. The \u003cstrong data-start=\"247\" data-end=\"291\"\u003eQuicksilver 816761Q4 Spark Plug Wire Kit\u003c\/strong\u003e keeps that spark steady in \u003cstrong data-start=\"319\" data-end=\"381\"\u003eV8 left-hand rotation MerCruiser engines (305 and 350 CID)\u003c\/strong\u003e equipped with \u003cstrong data-start=\"396\" data-end=\"443\"\u003eThunderbolt IV ignition systems (1981–1992)\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp data-start=\"448\" data-end=\"746\"\u003eEach wire in this OEM kit is built to exact Mercury specs — the right length, perfect resistance, and tight-fitting boots that keep moisture out. Made for life on the water, these wires hold up to heat, salt, and vibration, giving your engine a strong, consistent spark every time you fire it up.\u003c\/p\u003e\n\u003chr data-start=\"748\" data-end=\"751\"\u003e\n\u003ch3 data-start=\"753\" data-end=\"775\"\u003e\u003cstrong data-start=\"757\" data-end=\"773\"\u003eKey Features\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"778\" data-end=\"863\"\u003e\n\u003cstrong data-start=\"778\" data-end=\"790\"\u003ePurpose:\u003c\/strong\u003e Replaces old or worn plug wires to restore clean, consistent ignition.\u003c\/li\u003e\n\u003cli data-start=\"866\" data-end=\"1001\"\u003e\n\u003cstrong data-start=\"866\" data-end=\"878\"\u003eFitment:\u003c\/strong\u003e Designed for \u003cstrong data-start=\"892\" data-end=\"945\"\u003eV8 LH GM-based MerCruiser engines (305 \u0026amp; 350 CID)\u003c\/strong\u003e with \u003cstrong data-start=\"951\" data-end=\"998\"\u003eThunderbolt IV ignition systems (1981–1992)\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli data-start=\"1004\" data-end=\"1119\"\u003e\n\u003cstrong data-start=\"1004\" data-end=\"1021\"\u003eKit Contents:\u003c\/strong\u003e \u003cstrong data-start=\"1022\" data-end=\"1048\"\u003eEight spark plug wires\u003c\/strong\u003e with molded plug-end boots for a secure, water-resistant connection.\u003c\/li\u003e\n\u003cli data-start=\"1122\" data-end=\"1222\"\u003e\n\u003cstrong data-start=\"1122\" data-end=\"1133\"\u003eDesign:\u003c\/strong\u003e Each wire is \u003cstrong data-start=\"1147\" data-end=\"1165\"\u003efactory-length\u003c\/strong\u003e, cut precisely for the correct routing and plug reach.\u003c\/li\u003e\n\u003cli data-start=\"1225\" data-end=\"1339\"\u003e\n\u003cstrong data-start=\"1225\" data-end=\"1247\"\u003eMarine Durability:\u003c\/strong\u003e Engineered for \u003cstrong data-start=\"1263\" data-end=\"1307\"\u003eheat, moisture, and vibration resistance\u003c\/strong\u003e in tough marine environments.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1341\" data-end=\"1344\"\u003e\n\u003ch3 data-start=\"1346\" data-end=\"1383\"\u003e\u003cstrong data-start=\"1350\" data-end=\"1381\"\u003eEngine \u0026amp; Boat Compatibility\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli data-start=\"1386\" data-end=\"1453\"\u003eLeft-hand rotation GM-based V8 MerCruiser engines (305 \u0026amp; 350 CID)\u003c\/li\u003e\n\u003cli data-start=\"1456\" data-end=\"1501\"\u003eThunderbolt IV ignition systems (1981–1992)\u003c\/li\u003e\n\u003cli data-start=\"1504\" data-end=\"1578\"\u003eCommon in sport cruisers, inboard\/outboard boats, and classic tow setups\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1580\" data-end=\"1583\"\u003e\n\u003ch3 data-start=\"1585\" data-end=\"1627\"\u003e\u003cstrong data-start=\"1589\" data-end=\"1625\"\u003ePerformance \u0026amp; Practical Benefits\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"1628\" data-end=\"1923\"\u003eThe \u003cstrong data-start=\"1632\" data-end=\"1644\"\u003e816761Q4\u003c\/strong\u003e kit gives your ignition system a fresh start. The low-resistance cores keep spark voltage strong, ensuring smooth idle, quick starts, and crisp throttle response. Whether you’re idling through the marina or running at full plane, these wires keep every cylinder firing evenly.\u003c\/p\u003e\n\u003cp data-start=\"1925\" data-end=\"2229\"\u003eThe marine-grade insulation resists cracking and moisture, even after years of exposure. Each boot grips tight for a leak-free seal, so the spark energy goes where it’s supposed to — not lost to arcing or corrosion. You’ll feel smoother running and more consistent power from the first turn of the key.\u003c\/p\u003e\n\u003chr data-start=\"2231\" data-end=\"2234\"\u003e\n\u003ch3 data-start=\"2236\" data-end=\"2257\"\u003e\u003cstrong data-start=\"2240\" data-end=\"2255\"\u003eWhy Buy OEM\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"2258\" data-end=\"2522\"\u003eMercury’s OEM plug wires are built for the demands of marine engines — constant movement, salt exposure, and high operating temperatures. Aftermarket wires might fit, but they often use weaker insulation or generic resistance values that cause premature failure.\u003c\/p\u003e\n\u003cp data-start=\"2524\" data-end=\"2742\"\u003eA \u003cstrong data-start=\"2526\" data-end=\"2558\"\u003egenuine Quicksilver wire set\u003c\/strong\u003e gives you the right lengths, proper resistance, and long-lasting durability. It’s the same quality your engine was built with — tested, proven, and made to last season after season.\u003c\/p\u003e\n\u003chr data-start=\"2744\" data-end=\"2747\"\u003e\n\u003ch3 data-start=\"2749\" data-end=\"2762\"\u003e\u003cstrong data-start=\"2753\" data-end=\"2760\"\u003eFAQ\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"2763\" data-end=\"2956\"\u003e\u003cstrong data-start=\"2763\" data-end=\"2817\"\u003eQ1: What engines fit the Quicksilver 816761Q4 kit?\u003c\/strong\u003e\u003cbr data-start=\"2817\" data-end=\"2820\"\u003eA: It fits \u003cstrong data-start=\"2831\" data-end=\"2900\"\u003eV8 left-hand rotation GM-based MerCruiser engines (305 \u0026amp; 350 CID)\u003c\/strong\u003e with \u003cstrong data-start=\"2906\" data-end=\"2953\"\u003eThunderbolt IV ignition systems (1981–1992)\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp data-start=\"2958\" data-end=\"3080\"\u003e\u003cstrong data-start=\"2958\" data-end=\"2994\"\u003eQ2: How many wires are included?\u003c\/strong\u003e\u003cbr data-start=\"2994\" data-end=\"2997\"\u003eA: The kit includes \u003cstrong data-start=\"3017\" data-end=\"3043\"\u003eeight spark plug wires\u003c\/strong\u003e, all pre-fitted with molded boots.\u003c\/p\u003e\n\u003cp data-start=\"3082\" data-end=\"3220\"\u003e\u003cstrong data-start=\"3082\" data-end=\"3114\"\u003eQ3: Are they saltwater safe?\u003c\/strong\u003e\u003cbr data-start=\"3114\" data-end=\"3117\"\u003eA: Yes. The wires and terminals are built from corrosion-resistant materials designed for marine use.\u003c\/p\u003e\n\u003cp data-start=\"3222\" data-end=\"3352\"\u003e\u003cstrong data-start=\"3222\" data-end=\"3260\"\u003eQ4: How difficult is installation?\u003c\/strong\u003e\u003cbr data-start=\"3260\" data-end=\"3263\"\u003eA: Easy. Replace one wire at a time to maintain firing order — no special tools needed.\u003c\/p\u003e\n\u003cp data-start=\"3354\" data-end=\"3522\"\u003e\u003cstrong data-start=\"3354\" data-end=\"3393\"\u003eQ5: Why OEM instead of aftermarket?\u003c\/strong\u003e\u003cbr data-start=\"3393\" data-end=\"3396\"\u003eA: OEM wires fit perfectly, resist marine wear, and provide steady spark — aftermarket versions can’t match the consistency.\u003c\/p\u003e","brand":"Mercury","offers":[{"title":"Default Title","offer_id":46936069341475,"sku":"84-816761Q4","price":77.79,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0783\/7410\/9475\/files\/816761q4_main.jpg?v=1760631221","url":"https:\/\/partsvu.com\/en-au\/products\/mercury-mercruiser-spark-plug-wire-kit-fits-gm-v-8-305-350-cid-engines-with-thunderbolt-iv-ignition-84-816761q4","provider":"PartsVu","version":"1.0","type":"link"}