{"product_id":"ignition-coil-for-johnson-evinrude-3-4-cylinder-outboards-sierra-18-99321","title":"Sierra Ignition Coil 18-99321 for Johnson\/Evinrude 3 and 4 Cylinder Outboards","description":"\u003cp\u003eThe Sierra 18-99321 is an ignition coil built for Johnson and Evinrude outboard engines with 3 or 4 cylinder configurations. As a core component of the ignition system, the coil steps up battery voltage into the high-voltage pulse needed to fire the spark plugs, and a weak or failing coil is a common cause of hard starting, misfires, rough idle, or a no-spark condition on these outboards. This part is a bolt-on replacement, designed to install using the factory mounting points without modification.\u003c\/p\u003e\u003cp\u003eThe coil measures 4 x 3 x 3 inches and weighs 0.6 pounds. It is intended for marine personal watercraft and outboard applications where Johnson\/Evinrude 3 or 4 cylinder ignition coils are specified. Installing a properly matched ignition coil helps restore consistent spark energy and reliable engine starting.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-99321\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Ignition Coil\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Engine:\u003c\/strong\u003e Johnson\/Evinrude 3 or 4 Cylinder\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstallation Type:\u003c\/strong\u003e Bolt-On\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Dimensions:\u003c\/strong\u003e 4 x 3 x 3 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.6 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVehicle Service Type:\u003c\/strong\u003e Marine Personal Craft\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eJohnson\/Evinrude outboard engines, 3 Cylinder\u003c\/li\u003e\n\u003cli\u003eJohnson\/Evinrude outboard engines, 4 Cylinder\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines is the Sierra 18-99321 ignition coil designed for?\u003c\/strong\u003e The Sierra 18-99321 is designed for Johnson and Evinrude outboard engines with 3 or 4 cylinder configurations.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-99321 a direct bolt-on replacement?\u003c\/strong\u003e Yes, the 18-99321 ignition coil uses a bolt-on installation type, so it mounts using the existing factory hardware points without modification.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of this ignition coil?\u003c\/strong\u003e Sierra part 18-99321 measures 4 x 3 x 3 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-99321 ignition coil weigh?\u003c\/strong\u003e It weighs 0.6 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat symptoms indicate my ignition coil needs replacement?\u003c\/strong\u003e Hard starting, engine misfire, rough idle, or a complete loss of spark on a Johnson\/Evinrude 3 or 4 cylinder outboard are common signs that the ignition coil, such as the Sierra 18-99321, should be inspected and replaced.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-99321 work on both 3 cylinder and 4 cylinder Johnson\/Evinrude engines?\u003c\/strong\u003e Yes, the Sierra 18-99321 ignition coil is listed for both 3 cylinder and 4 cylinder Johnson\/Evinrude outboard engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-99321?\u003c\/strong\u003e The order includes one Sierra 18-99321 ignition coil, ready for bolt-on installation on a compatible Johnson\/Evinrude outboard.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this ignition coil intended for personal watercraft or outboard boats?\u003c\/strong\u003e The 18-99321 is classified for marine personal craft service and is used on Johnson\/Evinrude 3 or 4 cylinder outboard engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I install the Sierra 18-99321 myself?\u003c\/strong\u003e Because it is a bolt-on ignition coil, the 18-99321 can typically be installed with basic hand tools by removing the old coil and mounting the replacement in the same location, though buyers unfamiliar with marine ignition systems should have the installation checked by a qualified marine technician.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the ignition coil housing made of?\u003c\/strong\u003e Material composition for the Sierra 18-99321 is not specified in the available product data.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988441903323,"sku":"SIE-18-99321","price":54.09,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/CDI-183-2382_lg__42732.1558111232.500.750.jpg?v=1785188351","url":"https:\/\/www.goodvibesmarina.com\/products\/ignition-coil-for-johnson-evinrude-3-4-cylinder-outboards-sierra-18-99321","provider":"Good Vibes Marina","version":"1.0","type":"link"}