{"product_id":"sierra-trigger-mercury-18-99438","title":"Sierra Trigger Mercury #18-99438","description":"\u003ch2\u003eSierra 18-99438 Ignition Timer Base\u003c\/h2\u003e\n\u003cp\u003eThe Sierra 18-99438 is a precision-engineered ignition trigger (timer base) designed for Mercury SportJet and Force outboard engines. This critical ignition component generates the timing signals that control spark delivery to the engine's cylinders, ensuring proper ignition timing for optimal engine performance, smooth operation, and reliable starting across all operating conditions.\u003c\/p\u003e\n\u003cp\u003eThe ignition trigger works in conjunction with your engine's ignition system to precisely time spark delivery based on engine speed and position. When the trigger fails or malfunctions, you may experience symptoms including no spark, intermittent spark, misfiring, rough running, poor acceleration, difficulty starting, or complete engine failure. Replacing a faulty trigger restores proper ignition timing and returns your engine to reliable operation.\u003c\/p\u003e\n\u003cp\u003eManufactured to meet or exceed OEM specifications, this Sierra trigger provides the quality, precision, and reliability needed for trouble-free ignition system performance. The component is engineered to withstand the demanding conditions of marine engine operation, including vibration, heat, moisture, and electrical stress. Using quality replacement parts like this Sierra trigger ensures your ignition system functions properly and your engine delivers the performance and reliability you expect.\u003c\/p\u003e\n\u003cp\u003eThis trigger is designed as a direct replacement for the original equipment, ensuring proper fit and function without modification. The precise manufacturing tolerances ensure accurate timing signal generation, which is critical for maintaining proper engine performance, fuel efficiency, and emissions. Whether you're troubleshooting ignition problems or performing preventive maintenance, this Sierra trigger provides the quality needed to keep your engine running strong.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMercury SportJet: 1995 (120HP)\u003c\/li\u003e\n\u003cli\u003eForce: 1991-1995 (120HP)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eInterchange Numbers:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eCDI: 134-7029-4\u003c\/li\u003e\n\u003cli\u003eMercury Marine: 817029A11\u003c\/li\u003e\n\u003cli\u003eMercury Marine: 817029A4\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eKey Features:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ePrecision ignition trigger (timer base)\u003c\/li\u003e\n\u003cli\u003eDirect OEM replacement\u003c\/li\u003e\n\u003cli\u003eEnsures proper ignition timing\u003c\/li\u003e\n\u003cli\u003eRestores reliable engine operation\u003c\/li\u003e\n\u003cli\u003eQuality construction for marine environments\u003c\/li\u003e\n\u003cli\u003eCritical for starting and performance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cb\u003eNormalized SKU:\u003c\/b\u003e 1899438\u003cbr\u003e\u003cb\u003eUPC Code:\u003c\/b\u003e 808282394691\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":53193335931185,"sku":"SIE-18-99438","price":136.01,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0015\/7184\/8291\/files\/sierra-trigger-mercury-18-99438-808282394691-1227370070.jpg?v=1773641839","url":"https:\/\/www.firstchoicemarine.com\/products\/sierra-trigger-mercury-18-99438","provider":"First Choice Marine","version":"1.0","type":"link"}