{"product_id":"marine-stator-for-mercury-outboards-replaces-oem-398-5454a7-sierra-18-5857","title":"Sierra Stator 18-5857 for Mercury V225 Outboard, Serial 5628028 and Up, Replaces Mercury Marine 398-5454A7","description":"\u003cp\u003eThe Sierra 18-5857 is a replacement stator built for Mercury V225 outboard engines with serial number 5628028 and up. The stator is a key charging-system component mounted around the flywheel that generates AC current as the flywheel magnets pass by its windings, supplying power for ignition timing and battery charging. This unit is constructed with an aluminum housing and finished in white to match factory charging-system components, and it is rated for use in salt water applications as well as fresh water. It is designed as a direct replacement for the factory stator on applicable Mercury V225 engines, restoring proper charging output on engines where the original stator has failed, weakened, or shorted out. Because the stator sits close to the flywheel and is exposed to engine heat and marine moisture, using a properly rated replacement matched to the correct engine and serial number range is important for reliable starting and charging performance. The Sierra 18-5857 corresponds to the equivalent Mercury Marine part 398-5454A7, making it straightforward to identify against the original equipment number when sourcing a replacement. Boat owners and marine technicians use this part when diagnosing no-charge or intermittent-charge conditions, weak battery charging, or stator failure confirmed by resistance testing.\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 18-5857\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Type:\u003c\/strong\u003e Stator\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 3.2 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Type:\u003c\/strong\u003e 4 Stroke\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting Type:\u003c\/strong\u003e Transom Mount\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFuel Type:\u003c\/strong\u003e Gasoline\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRecommended Use:\u003c\/strong\u003e For Salt Water\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999563835\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Equivalent Part Number:\u003c\/strong\u003e Mercury Marine 398-5454A7\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury V225, serial number 5628028 and up\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e398-5454A7\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-5857 stator fit?\u003c\/strong\u003e The Sierra 18-5857 is built for Mercury V225 outboard engines with serial number 5628028 and up.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-5857 a direct replacement for the Mercury OEM stator?\u003c\/strong\u003e Yes, the 18-5857 is the equivalent replacement for Mercury Marine part 398-5454A7 and is designed to be a direct swap on applicable V225 engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the 18-5857 made of?\u003c\/strong\u003e It has an aluminum housing finished in white, matching the factory charging-system components on Mercury V225 outboards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-5857 stator weigh?\u003c\/strong\u003e The Sierra 18-5857 weighs 3.2 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-5857 be used in salt water?\u003c\/strong\u003e Yes, this stator is rated for use in salt water applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does a stator do on an outboard engine?\u003c\/strong\u003e A stator is the charging-system component mounted around the flywheel that generates AC current as the flywheel magnets rotate past it, supplying power for ignition and battery charging; the Sierra 18-5857 performs this function on Mercury V225 outboards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if my Mercury V225 needs this stator?\u003c\/strong\u003e Symptoms such as weak battery charging, no charge output, or intermittent charging combined with a failed stator resistance test on a serial-5628028-and-up V225 engine indicate the 18-5857 replacement stator is needed.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-5857?\u003c\/strong\u003e The order includes the Sierra 18-5857 stator itself; no additional hardware is specified for this part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-5857 genuine Mercury or aftermarket?\u003c\/strong\u003e The 18-5857 is a Sierra-brand replacement stator manufactured to match the Mercury Marine 398-5454A7 equivalent, rather than a genuine Mercury-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the serial number range matter when ordering this stator?\u003c\/strong\u003e Yes, the Sierra 18-5857 is specified for Mercury V225 engines with serial number 5628028 and up, so confirming the engine serial number is important before ordering.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat UPC is associated with the Sierra 18-5857 stator?\u003c\/strong\u003e The Sierra 18-5857 stator carries UPC 030999563835.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988335866075,"sku":"SIE-18-5857","price":259.38,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/Untitled-1__04770.1753840680.500.750.jpg?v=1785188013","url":"https:\/\/www.goodvibesmarina.com\/products\/marine-stator-for-mercury-outboards-replaces-oem-398-5454a7-sierra-18-5857","provider":"Good Vibes Marina","version":"1.0","type":"link"}