{"product_id":"meilan-spark-plugs-for-marine-outboards-inboards-ql78yc-6-pack-14mm-thread-projected-tip","title":"MEILAN Spark Plugs for Marine Outboards \u0026 Inboards QL78YC 6-Pack — 14mm Thread, Projected Tip","description":"\u003cp\u003e\u003cstrong\u003eMEILAN 6-pack spark plugs (QL78YC 24 \/ QL78YC-6PK) are OEM-compatible replacement plugs designed for many marine outboard and inboard engines, supplied as six standard projected-tip, 14mm-thread plugs.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThese replacement spark plugs are bulk-packed and built to Champion specifications to fit a range of boats and marine powerheads. They feature a 14mm thread diameter, 12.7mm reach, a flat seat, 21mm hex for wrenching, and a projected tip with a solid terminal. Sold as a pack of six, the plugs arrive new and ready for installation — but always verify the correct part number in your engine's owner manual before fitting.\u003c\/p\u003e\n\n\u003ch3\u003eWhich engines will these plugs fit?\u003c\/h3\u003e\n\u003cp\u003eThe MEILAN QL78YC 6-pack is intended as a Genuine Champion-compatible replacement for many outboard and inboard marine engines that specify the QL78YC family. Compatibility depends on thread size, reach, and seat type rather than brand alone, so confirm cross-reference details for your model.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThread: 14mm — common on many small to mid-size marine engines.\u003c\/li\u003e\n  \u003cli\u003eReach: 12.7mm — matches engines requiring that electrode extension.\u003c\/li\u003e\n  \u003cli\u003eFlat seat and projected tip — ensure compatibility with your combustion chamber design.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I install these spark plugs correctly?\u003c\/h3\u003e\n\u003cp\u003eInstallation requires basic hand tools and attention to torque and gap. Hand-start the plug to avoid cross-threading, use the specified torque or a torque wrench, and confirm the electrode gap per your owner's manual before installation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eHand-thread first to prevent damage to cylinder head threads.\u003c\/li\u003e\n  \u003cli\u003eUse a 21mm socket to tighten to manufacturer torque specs.\u003c\/li\u003e\n  \u003cli\u003eCheck or set the spark gap to the engine maker’s recommendation before fitting.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat are the plug’s key specifications and why they matter?\u003c\/h3\u003e\n\u003cp\u003eThese characteristics determine fit, sealing, reach into the combustion chamber, and suitability for your engine’s ignition system. Matching specs prevents combustion issues, misfires, and mechanical damage.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eType: Standard, projected-tip — positions the electrode for reliable ignition.\u003c\/li\u003e\n  \u003cli\u003eTerminal: Solid — compatible with standard marine ignition leads or caps.\u003c\/li\u003e\n  \u003cli\u003eHex size: 21mm — fits common spark plug sockets for service.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAre these genuine Champion plugs and what does ‘bulk packed’ mean?\u003c\/h3\u003e\n\u003cp\u003eThe MEILAN listing supplies the Champion-compatible part number QL78YC-6PK as a genuine replacement reference. Bulk packed means the plugs are packaged together without individual retail boxes, ideal for servicing multiple cylinders at once.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eGenuine replacement reference: QL78YC-6PK for cross-checking.\u003c\/li\u003e\n  \u003cli\u003eBulk packed: cost-efficient for mechanics or multi-plug maintenance.\u003c\/li\u003e\n  \u003cli\u003eNew condition: ready for immediate fitment following installation best practices.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this product for? Boat owners, marine mechanics, and hobbyists who maintain outboard or inboard engines and need an economical six-pack of OEM-replacement spark plugs will find this kit useful. It’s best for anyone who has verified that their engine calls for a 14mm thread, 12.7mm reach, flat seat, and projected tip configuration. If you’re uncertain about fitment, consult your engine’s service manual or check cross-reference lists before installing.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Do these spark plugs fit all marine engines?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: They fit engines specifying 14mm thread, 12.7mm reach, flat seat and projected tip; check your owner’s manual or cross-reference list first.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Should I set the gap before installation?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — verify and adjust the electrode gap to the engine manufacturer’s specification before installing.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"MEILAN","offers":[{"title":"Default Title","offer_id":48082954780830,"sku":"B0872RV1B1","price":50.8,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/meilan-spark-plugs-front-packaging.jpg?v=1785820209","url":"https:\/\/northtrailauto.ca\/products\/meilan-spark-plugs-for-marine-outboards-inboards-ql78yc-6-pack-14mm-thread-projected-tip","provider":"North Trail Auto","version":"1.0","type":"link"}