{"product_id":"namura-na-50080k-top-end-kit-79-95-mm-standard-bore-11-1-compression-for-polaris-800","title":"Namura NA-50080K Top End Kit, 79.95 mm Standard Bore, 11:1 Compression for Polaris 800","description":"\u003cp\u003eThe Namura NA-50080K Top End Kit is a complete standard-bore replacement package designed for select Polaris 800 engines. This 79.95 mm, 11:1 compression kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit for a convenient rebuild solution. The kit is supplied under manufacturer part number NA-50080K and vendor part number 186-5080.\u003c\/p\u003e\u003cp\u003eThe piston features MOS2, or Teflon\/molybdenum, coated skirts applied through a rolled-on process designed to provide a stronger bond than conventional spray-on coatings. This treatment helps reduce friction, improve heat transfer, and minimize the risk of cold seizures. Machined smooth heads reflect combustion heat and help reduce carbon buildup, supporting piston protection and consistent engine performance.\u003c\/p\u003e\u003cp\u003eAnodized domes improve heat resistance and durability, while the hypereutectic casting process provides increased silicon content for reduced thermal expansion, added wear resistance, and improved ability to withstand elevated cylinder temperatures. These features make the Namura kit a practical choice for restoring top-end performance during engine service.\u003c\/p\u003e\u003cp\u003eFitment includes the 2010 Polaris Ranger Crew 800 4x4; 2008–2010 Polaris RZR 800; 2010 Polaris RZR 800 S; 2009–2010 Polaris Sportsman Big Boss 6X6 800; 2008 Polaris Sportsman Touring 800; and 2007 Polaris Sportsman X2 800 EFI. Verify the model, year, bore specification, and compression requirements before installation.\u003c\/p\u003e\u003cp\u003e\u003cb\u003eFeatures:\u003c\/b\u003e\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eComplete Top End Kit: Includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit.\u003c\/li\u003e\n\u003cli\u003eMOS2-Coated Skirts: Rolled-on Teflon\/molybdenum coating helps reduce friction, improve heat transfer, and minimize cold-seizure risk.\u003c\/li\u003e\n\u003cli\u003eMachined Smooth Head: Helps reflect combustion heat and reduce carbon buildup for improved piston protection.\u003c\/li\u003e\n\u003cli\u003eAnodized Dome: Increases piston heat resistance and durability.\u003c\/li\u003e\n\u003cli\u003eHypereutectic Construction: Provides reduced expansion, increased wear resistance, and improved high-temperature performance.\u003c\/li\u003e\n\u003cli\u003eStandard Bore Fitment: 79.95 mm standard-bore piston with an 11:1 compression ratio for select Polaris 800 applications.\u003c\/li\u003e\n\u003cli\u003eVehicle Compatibility: Fits select Polaris Ranger, RZR, Sportsman Big Boss, Sportsman Touring, and Sportsman X2 800 models.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n2005 Polaris Sportsman 800 EFI\u003cbr\u003e\n2006 Polaris Sportsman 800 EFI\u003cbr\u003e\n2007 Polaris Sportsman 800 EFI\u003cbr\u003e\n2007 Polaris Sportsman X2 800 EFI\u003cbr\u003e\n2008 Polaris RZR 800\u003cbr\u003e\n2008 Polaris Sportsman Touring 800\u003cbr\u003e\n2008 Polaris Sportsman X2 800 EFI\u003cbr\u003e\n2009 Polaris RZR 800\u003cbr\u003e\n2009 Polaris Sportsman Big Boss 6X6 800\u003cbr\u003e\n2009 Polaris Sportsman Touring 800\u003cbr\u003e\n2009 Polaris Sportsman X2 800 EFI\u003cbr\u003e\n2010 Polaris Ranger 800 4x4\u003cbr\u003e\n2010 Polaris Ranger 800 6X6\u003cbr\u003e\n2010 Polaris Ranger Crew 800 4x4\u003cbr\u003e\n2010 Polaris RZR 800\u003cbr\u003e\n2010 Polaris RZR 800 S\u003cbr\u003e\n2010 Polaris Sportsman 800 EFI\u003cbr\u003e\n2010 Polaris Sportsman Big Boss 6X6 800","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67558606864619,"sku":"186-5080","price":268.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/ac12-5d76d55d469e7_7baeb7a6-df88-4964-b79d-100bcd56f722.jpg?v=1790767521","url":"https:\/\/ctracingservices.com\/products\/namura-na-50080k-top-end-kit-79-95-mm-standard-bore-11-1-compression-for-polaris-800","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}