{"product_id":"yamaha-50-hp-ignition-pack-cdi-power-pack-replaces-oem-6h4-85540-20-00-fits-3-cyl-2-stroke-1984-1988-sierra-18-99304","title":"Sierra Ignition Pack 18-99304 for Yamaha 3 Cylinder 50 HP 1984-1988 2-Stroke Outboards, Replaces 6H4-85540-20-00","description":"\u003cp\u003eThe Sierra 18-99304 Ignition Pack is a replacement ignition control module built for Yamaha 3 cylinder 50 HP 2-stroke outboard motors, 1984-1988, all models. The ignition pack manages spark timing and delivery to the engine's cylinders, and is a common wear item on outboards of this age as internal components degrade with heat cycling and vibration over years of service. Installing a fresh unit restores reliable spark output, helping resolve hard starting, rough idle, misfires, or a complete no-spark condition traced to the ignition pack itself.\u003c\/p\u003e\u003cp\u003eThis part is sold under Sierra part number 18-99304 and is built to meet or exceed the output and durability of the original Yamaha ignition pack it replaces. It mounts in the same location as the factory unit and uses the same electrical connections, so installation follows the same steps as removing and replacing the original ignition pack.\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 18-99304\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Yamaha Outboard Ignition System\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.9 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282396084\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinders:\u003c\/strong\u003e 3\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eYamaha 3 Cylinder 50 HP, 1984-1988, 2-Stroke, All Models\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e6H4-85540-20-00\u003c\/li\u003e\n\u003cli\u003e6H4-85540-21-00\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-99304 ignition pack fit?\u003c\/strong\u003e It fits Yamaha 3 cylinder 50 HP outboard motors, 1984-1988, 2-stroke, all models.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-99304 an OEM part or an aftermarket replacement?\u003c\/strong\u003e The 18-99304 is an aftermarket ignition pack built to replace the original Yamaha ignition pack, not an OEM Yamaha part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich OEM part numbers does the 18-99304 replace?\u003c\/strong\u003e The Sierra 18-99304 ignition pack replaces Yamaha OEM numbers 6H4-85540-20-00 and 6H4-85540-21-00.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does this ignition pack weigh?\u003c\/strong\u003e The Sierra 18-99304 ignition pack weighs 0.9 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat symptoms indicate my ignition pack needs replacement?\u003c\/strong\u003e Hard starting, rough idle, engine misfire, or a complete loss of spark on a Yamaha 3 cylinder 50 HP 2-stroke outboard can indicate a failing ignition pack, which the 18-99304 is designed to replace.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-99304 work on 4-stroke Yamaha 50 HP engines?\u003c\/strong\u003e No, the 18-99304 is built for the Yamaha 3 cylinder 50 HP 2-stroke outboard, 1984-1988, all models.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-99304?\u003c\/strong\u003e The order includes one Sierra 18-99304 ignition pack for the Yamaha 3 cylinder 50 HP 2-stroke outboard.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes installing the 18-99304 require special tools?\u003c\/strong\u003e Installation follows the same mounting location and electrical connections as the original Yamaha ignition pack it replaces, so no specialized tools beyond standard hand tools are needed.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use the 18-99304 on a different horsepower Yamaha outboard?\u003c\/strong\u003e The 18-99304 is specified for the Yamaha 3 cylinder 50 HP 2-stroke outboard, 1984-1988, all models, so it should be matched to that engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-99304 a direct fit replacement?\u003c\/strong\u003e Yes, the 18-99304 is designed as a direct replacement for the Yamaha ignition pack carrying OEM numbers 6H4-85540-20-00 and 6H4-85540-21-00.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988441084123,"sku":"SIE-18-99304","price":610.82,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/CDI-117-6H4-21_lg__69162.1558112891.500.750.jpg?v=1785187978","url":"https:\/\/www.goodvibesmarina.com\/products\/yamaha-50-hp-ignition-pack-cdi-power-pack-replaces-oem-6h4-85540-20-00-fits-3-cyl-2-stroke-1984-1988-sierra-18-99304","provider":"Good Vibes Marina","version":"1.0","type":"link"}