{"product_id":"sierra-18-3972-marine-piston-ring-set-standard-for-johnson-evinrude-5-8-hp-outboards-replaces-omc-390082","title":"Sierra Piston Ring 18-3972 for Johnson\/Evinrude 5\/6\/8\/7.5 HP Outboards, 1986-95, 1.937 Inch Standard Bore","description":"\u003cp\u003eThe Sierra 18-3972 is a standard-bore piston ring for Johnson\/Evinrude (OMC) outboard motors, engineered as a direct replacement for the factory ring set on applicable powerheads. It is sized for a 1.937 inch standard bore and is intended for use in 2-cylinder engines rated 5, 6, 8, and 7.5 horsepower for the 1986-95 model years, with the exception of 1991 60-degree V models. The ring is manufactured from alloy steel and cast iron for wear resistance and a reliable seal against the cylinder wall, helping maintain compression and reduce blow-by during a rebuild or piston service.\u003c\/p\u003e\u003cp\u003eThis is a standard-size ring, matched to the original bore diameter rather than an oversize\/overbore replacement, making it the correct choice when the cylinder has not been bored out. It ships as a single unit count and is backed by Sierra's standard limited warranty, giving technicians and DIY boaters a dependable component for internal engine repair work on compatible Johnson\/Evinrude powerheads.\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 18-3972\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Piston Ring\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Type:\u003c\/strong\u003e Piston Rings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard Bore:\u003c\/strong\u003e 1.937 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder Configuration:\u003c\/strong\u003e 2-cylinder\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRing Size:\u003c\/strong\u003e Standard\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Alloy Steel, Cast Iron\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.03 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded Components:\u003c\/strong\u003e Piston Rings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282235055, 707390455778\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e Sierra Limited Warranty\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eJohnson\/Evinrude (OMC) outboard, 5\/6\/8\/7.5 HP, 2-cylinder, 1986-95, except 1991 60-degree V models\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eOMC 390082\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-3972 piston ring fit?\u003c\/strong\u003e It fits Johnson\/Evinrude (OMC) 2-cylinder outboards rated 5, 6, 8, and 7.5 HP for the 1986-95 model years, except 1991 60-degree V models.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat bore size is this ring made for?\u003c\/strong\u003e The 18-3972 is sized for a 1.937 inch standard bore, not an oversize or bored-out cylinder.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-3972 a standard ring or an oversize ring?\u003c\/strong\u003e It is a standard ring, matched to the factory bore diameter rather than a.020 or.030 oversize replacement.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does the 18-3972 replace?\u003c\/strong\u003e The Sierra 18-3972 replaces OMC part number 390082.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the 18-3972 ring made of?\u003c\/strong\u003e It is made of alloy steel and cast iron, materials chosen for wear resistance and a durable seal against the cylinder wall.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many rings come in the package?\u003c\/strong\u003e The Sierra 18-3972 is sold as a single unit count of piston rings for one piston.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-3972 piston ring weigh?\u003c\/strong\u003e It weighs 0.03 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this ring work on a 1991 60-degree V model?\u003c\/strong\u003e No, the 18-3972 fitment for 5\/6\/8\/7.5 HP 1986-95 engines specifically excludes 1991 60-degree V models.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-3972 genuine Sierra or aftermarket?\u003c\/strong\u003e The 18-3972 is a genuine Sierra part, sold as a direct-fit replacement for the OMC piston ring on covered Johnson\/Evinrude powerheads.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the cylinder count for engines using the 18-3972?\u003c\/strong\u003e The 18-3972 is designed for 2-cylinder Johnson\/Evinrude outboards in the 5\/6\/8\/7.5 HP range.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-3972 come with a warranty?\u003c\/strong\u003e Yes, the Sierra 18-3972 is covered by Sierra's limited warranty.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988170354907,"sku":"SIE-18-3972","price":20.94,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-3972__04291.1722491809.500.750.jpg?v=1785188925","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-3972-marine-piston-ring-set-standard-for-johnson-evinrude-5-8-hp-outboards-replaces-omc-390082","provider":"Good Vibes Marina","version":"1.0","type":"link"}