{"product_id":"champion-ql77jc4-marine-spark-plug-828m-4-pack-mercury-4-stroke-24-ql77jc4","title":"Champion QL77JC4 Marine Spark Plug | #828M | 4-Pack | Mercury 4-Stroke Outboard","description":"\u003ch2\u003eThe Standard Spark Plug for Mercury 4-Stroke Outboards — 4-Pack.\u003c\/h2\u003e\u003cp\u003eThe Champion QL77JC4 is one of the most widely specified marine spark plugs for Mercury 4-stroke outboard engines. Part number 828M, the JC4 design features four ground electrodes arranged around a fine-wire centre electrode — delivering more consistent spark initiation, improved ignitability, and longer service life compared to a standard single-ground plug.\u003c\/p\u003e\u003cp\u003eThe QL-series long-reach thread and projected tip are engineered for the combustion chamber geometry of Mercury 4-stroke outboards. Sold in a 4-pack (Champion part 12198) — enough for most 4-cylinder outboard applications. Always verify fitment against your engine's owner's manual before ordering.\u003c\/p\u003e\u003ch3\u003eKey Features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eChampion QL77JC4 marine spark plug — 4-pack (Champion #828M)\u003c\/li\u003e\n\u003cli\u003eFour ground electrodes for consistent spark initiation and improved ignitability\u003c\/li\u003e\n\u003cli\u003eFine-wire centre electrode for reduced voltage requirement and longer service life\u003c\/li\u003e\n\u003cli\u003eLong-reach QL-series thread with projected tip — engineered for Mercury 4-stroke outboard combustion chambers\u003c\/li\u003e\n\u003cli\u003eResistor construction suppresses radio frequency interference (RFI)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMercury 4-stroke outboard engines specifying Champion QL77JC4 or equivalent\u003c\/li\u003e\n\u003cli\u003eApplications cross-referencing Mercury OEM spark plug part 896329828\u003c\/li\u003e\n\u003cli\u003eMercury 4-stroke outboards where the owner's manual specifies a QL77JC4 or equivalent plug\u003c\/li\u003e\n\u003cli\u003eVerify fitment using your engine's owner's manual or the Champion spark plug application guide\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\u003cp\u003eThe QL77JC4 is the plug to reach for on most Mercury 4-stroke outboard tune-ups — it's the OEM-specified plug for a wide range of Mercury 4-stroke models and is one of the most commonly replaced marine spark plugs we carry. Mercury recommends replacing spark plugs every 100 hours or annually, whichever comes first. If you're doing a full tune-up, pair the plug replacement with a fuel filter and gear oil service for best results.\u003c\/p\u003e\u003cp\u003eAlso available in a shop pack of 24 — see the \u003ca href=\"\/products\/champion-spark-plug-828s-shop-pack-of-24-66020-24-ql77jc4sp\"\u003eChampion #828S Shop Pack\u003c\/a\u003e if you're servicing a fleet or stocking up for the season. For the NGK equivalent commonly used in Mercury 4-stroke outboards, see the \u003ca href=\"\/products\/quicksilver-ngk-iridium-spark-plug-set-889246q39\"\u003eQuicksilver NGK Iridium Spark Plug Set\u003c\/a\u003e. For other Champion QL-series marine plugs, see the \u003ca href=\"\/products\/champion-ql16v-marine-spark-plug-876m-4-pack-long-reach-2-stroke-outboard-24-ql16v\"\u003eChampion QL16V #876M\u003c\/a\u003e or \u003ca href=\"\/products\/champion-spark-plugs-ql78yc-938m-4-pack-12217-24-ql78yc\"\u003eChampion QL78YC #938M\u003c\/a\u003e.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51250815008804,"sku":"24-QL77JC4","price":11.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/24-L76V_59cdbacb-6e11-4263-a166-68c1b1a00fae.jpg?v=1786510602","url":"https:\/\/marisolmarine.com\/products\/champion-ql77jc4-marine-spark-plug-828m-4-pack-mercury-4-stroke-24-ql77jc4","provider":"Marisol Marine Company","version":"1.0","type":"link"}