{"product_id":"sierra-18-5139-marine-contact-set-points-for-mercury-mariner-outboards-replaces-oem-336-4318a2","title":"Sierra 18-5139 Contact Set - Replaces Mercury\/Mariner 336-4318A2 for Outboard Motors","description":"\u003cp\u003eThe Sierra 18-5139 is a replacement ignition contact set (points) for Mercury\/Mariner outboard motors. Contact sets are a core ignition tune-up component, opening and closing to time the spark at each cylinder; worn, pitted, or misaligned points cause hard starting, rough idle, misfires, and lost power, so replacing them on schedule during a tune-up keeps ignition timing accurate and the engine running smoothly. The set is built with an aluminum construction and finished in white.\u003c\/p\u003e\u003cp\u003eThis is packaged as a direct equivalent to the Mercury Marine OEM contact set: two units of the Sierra 18-5139 equal one OEM 336-4318A2 contact set, so order quantity accordingly to match the OEM package count. It is commonly installed alongside a matching condenser as part of a full ignition tune-up on Mercury\/Mariner outboards. Every Sierra part carries Sierra's standard customer satisfaction warranty.\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 18-5139\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Ignition Contact Set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Application:\u003c\/strong\u003e Mercury\/Mariner Outboard Motor\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Aluminum\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999318367\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging Note:\u003c\/strong\u003e 2 x Sierra 18-5139 = 1 x OEM 336-4318A2\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury\/Mariner outboard motors\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e336-4318A2\u003c\/li\u003e\n\u003cli\u003e336-4318A4\u003c\/li\u003e\n\u003cli\u003e336-4318A3\u003c\/li\u003e\n\u003cli\u003e336-3948A3\u003c\/li\u003e\n\u003cli\u003e336-3948A2\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-5139 contact set replace?\u003c\/strong\u003e The Sierra 18-5139 is a direct equivalent for Mercury Marine OEM contact sets 336-4318A2, 336-4318A4, 336-4318A3, 336-3948A3, and 336-3948A2.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many contact sets come in a package of the 18-5139?\u003c\/strong\u003e Two units of the Sierra 18-5139 equal one OEM 336-4318A2 contact set, so check your engine's original packaging quantity when ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is a contact set used for on an outboard motor?\u003c\/strong\u003e A contact set, also called ignition points, opens and closes to time the spark delivered to each cylinder; it is a standard wear item replaced during an ignition tune-up on Mercury\/Mariner outboard motors.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the 18-5139 contact set fit?\u003c\/strong\u003e This contact set is designed for Mercury\/Mariner outboard motors that use the OEM 336-4318A2 series contact set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the 18-5139 contact set made of?\u003c\/strong\u003e The Sierra 18-5139 has an aluminum construction and is finished in white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-5139 contact set weigh?\u003c\/strong\u003e The Sierra 18-5139 contact set weighs 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-5139 a genuine Sierra part or aftermarket equivalent?\u003c\/strong\u003e It is a Sierra-branded aftermarket replacement engineered to the same fit and function as the Mercury Marine OEM contact sets it replaces, and it is covered by Sierra's standard customer satisfaction warranty.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I need to replace the condenser at the same time as the 18-5139 contact set?\u003c\/strong\u003e Contact sets are commonly replaced together with a matching condenser as part of a full ignition tune-up, though the condenser is a separate Sierra part number from the 18-5139 contact set.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-5139?\u003c\/strong\u003e Each order of Sierra 18-5139 includes the contact set only; remember that two units equal one OEM 336-4318A2 set, so verify quantity needed for your tune-up.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the signs a contact set needs replacing?\u003c\/strong\u003e Hard starting, rough idle, misfiring, and reduced power are common symptoms of worn or pitted contact points, and installing the Sierra 18-5139 restores accurate ignition timing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I cross-reference the 18-5139 using an OEM Mercury part number?\u003c\/strong\u003e Yes, the Sierra 18-5139 cross-references to Mercury Marine 336-4318A2, 336-4318A4, 336-4318A3, 336-3948A3, and 336-3948A2.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988199747803,"sku":"SIE-18-5139","price":50.25,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-5139_lg__73349.1558127924.500.750.jpg?v=1785189181","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-5139-marine-contact-set-points-for-mercury-mariner-outboards-replaces-oem-336-4318a2","provider":"Good Vibes Marina","version":"1.0","type":"link"}