{"product_id":"namura-na-50012-2k-87-43-mm-0-50-mm-top-end-kit-for-polaris-850-models","title":"NAMURA NA-50012-2K 87.43 mm +0.50 mm Top End Kit for Polaris 850 Models","description":"\u003cp\u003eThe NAMURA NA-50012-2K Top End Kit is designed for select Polaris 850 applications and includes the essential components needed for a reliable top-end rebuild. This kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit. With an 11:1 compression ratio and an 87.43 mm +0.50 mm piston size, it provides a precise replacement solution for compatible engines.\u003c\/p\u003e\u003cp\u003eThe piston features NAMURA’s MOS2, or Teflon and molybdenum, coated skirts. This rolled-on coating process creates a bond that is significantly stronger than many spray-applied alternatives, helping improve heat transfer, reduce friction, and minimize the risk of cold seizures. The machined smooth head helps reflect combustion heat and reduce carbon buildup, supporting piston protection and consistent engine performance.\u003c\/p\u003e\u003cp\u003eAn anodized dome increases heat resistance and durability, while NAMURA’s hypereutectic casting process provides increased silicon content for reduced expansion, added wear resistance, and improved tolerance of higher cylinder temperatures. These features make the NA-50012-2K a practical choice for restoring dependable performance in compatible Polaris engines.\u003c\/p\u003e\u003cp\u003eFitment includes the 2015–2017 Polaris Sportsman 850 SP, 2015–2017 Polaris Sportsman Touring 850 SP, 2014 Polaris Scrambler XP 850, 2014 Polaris Scrambler XP 850 EPS, 2012 Polaris Sportsman Touring 850 EPS, and 2013 Polaris Sportsman Touring 850 EPS. Verify the year, model, bore specification, and engine configuration before installation. Manufacturer part number: NA-50012-2K. Vendor part number: 186-50122.\u003c\/p\u003e\u003cp\u003e\u003cb\u003eFeatures:\u003c\/b\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eComplete top-end kit with piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit\u003c\/li\u003e\n\u003cli\u003e87.43 mm +0.50 mm piston size with an 11:1 compression ratio\u003c\/li\u003e\n\u003cli\u003eMOS2 Teflon and molybdenum coated skirts help reduce friction, improve heat transfer, and minimize cold-seizure risk\u003c\/li\u003e\n\u003cli\u003eMachined smooth piston head helps reflect combustion heat and reduce carbon buildup\u003c\/li\u003e\n\u003cli\u003eAnodized dome increases heat resistance and piston durability\u003c\/li\u003e\n\u003cli\u003eHypereutectic casting process provides reduced expansion, increased wear resistance, and improved high-temperature performance\u003c\/li\u003e\n\u003cli\u003eFits select 2012–2017 Polaris Sportsman, Sportsman Touring, and Scrambler XP 850 models\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n2012 Polaris Sportsman Touring 850 EPS\u003cbr\u003e\n2013 Polaris Scrambler XP 850\u003cbr\u003e\n2013 Polaris Scrambler XP 850 EPS\u003cbr\u003e\n2013 Polaris Sportsman Touring 850 EPS\u003cbr\u003e\n2013 Polaris Sportsman XP 850 EPS\u003cbr\u003e\n2014 Polaris Scrambler XP 850\u003cbr\u003e\n2014 Polaris Scrambler XP 850 EPS\u003cbr\u003e\n2014 Polaris Sportsman Touring 850 EPS\u003cbr\u003e\n2015 Polaris Sportsman 850 SP\u003cbr\u003e\n2015 Polaris Sportsman Touring 850 SP\u003cbr\u003e\n2016 Polaris Sportsman 850 SP\u003cbr\u003e\n2016 Polaris Sportsman Touring 850 SP\u003cbr\u003e\n2017 Polaris Sportsman 850 SP\u003cbr\u003e\n2017 Polaris Sportsman Touring 850 SP\u003cbr\u003e\n2018 Polaris Sportsman 850 SP\u003cbr\u003e\n2018 Polaris Sportsman Touring 850 SP","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67558635340011,"sku":"186-50122","price":295.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/183f-5b0d6accdc571_24887a63-2dab-4a7a-8373-3dd41f952f89.jpg?v=1790768410","url":"https:\/\/ctracingservices.com\/products\/namura-na-50012-2k-87-43-mm-0-50-mm-top-end-kit-for-polaris-850-models","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}