{"product_id":"sierra-88021-premium-marine-spark-plug-wire-set-47-88021","title":"Sierra Premium Marine Spark Plug Wire Set – 47-88021 | MerCruiser Thunderbolt","description":"\u003ch2\u003eSierra Premium Marine Spark Plug Wire Set – MerCruiser Thunderbolt Ignition\u003c\/h2\u003e\u003cp\u003eUpgrade your ignition system with this premium spark plug wire set engineered specifically for MerCruiser Thunderbolt ignition applications. Worn or cracked plug wires are a leading cause of misfires, rough idle, and power loss on the water — this Sierra set restores clean, consistent spark delivery with materials built to handle the heat, vibration, and moisture of a marine environment.\u003c\/p\u003e\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMerCruiser engines equipped with Thunderbolt ignition systems\u003c\/li\u003e\n\u003cli\u003eRefer to Sierra part number 47-88021 application guide for specific engine models and years\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eKey Features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eKevlar® core\u003c\/strong\u003e — maximum durability and long service life\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStainless steel wound conductor\u003c\/strong\u003e — optimized for maximum horsepower and engine performance\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePremium silicone jacketing and boots\u003c\/strong\u003e — high-temperature protection against engine heat\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSuperior RFI suppression\u003c\/strong\u003e — protects sensitive onboard electronics from interference\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrosion-resistant stainless steel terminals\u003c\/strong\u003e — at both spark plug and distributor ends for maximum conductivity\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOE-style sealed boots\u003c\/strong\u003e — barrier against heat, dirt, and moisture intrusion\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMagnetic suppression core\u003c\/strong\u003e — application-specific design for precise fit\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 47-88021\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIgnition Type:\u003c\/strong\u003e Thunderbolt (MerCruiser)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e New\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eComplete Your Ignition Service\u003c\/h3\u003e\u003cp\u003eFor a full tune-up, pair these wires with a matching distributor cap and rotor. Browse the \u003ca href=\"\/collections\/ignition-components\"\u003eIgnition Components\u003c\/a\u003e collection, or consider the \u003ca href=\"\/products\/sierra-v8-marine-spark-plug-wire-set-18-8820-1\"\u003eSierra V8 Marine Spark Plug Wire Set – 18-8820-1\u003c\/a\u003e or the \u003ca href=\"\/products\/sierra-magforce-4-cylinder-mercruiser-470-spark-plug-wire-set-18-8808-2\"\u003eSierra MagForce 4-Cylinder MerCruiser 470 Wire Set – 18-8808-2\u003c\/a\u003e if you need an alternate fitment.\u003c\/p\u003e\u003chr\u003e\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\u003cp\u003eThis wire set is the right call when a MerCruiser Thunderbolt-equipped engine is showing signs of ignition breakdown — misfiring under load, rough idle at low RPM, or intermittent spark. It’s also a smart preventive replacement during any major tune-up, especially on engines with high hours or several seasons of use. The silicone construction and sealed boots make this set particularly well-suited to bilge-adjacent routing where heat and moisture exposure are highest. Always replace the full set rather than individual wires to ensure consistent resistance across all cylinders.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51250810454052,"sku":"47-88021","price":131.49,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/47-88371.jpg?v=1786510561","url":"https:\/\/marisolmarine.com\/products\/sierra-88021-premium-marine-spark-plug-wire-set-47-88021","provider":"Marisol Marine Company","version":"1.0","type":"link"}