{"product_id":"namura-na-50025-4k-top-end-kit-79-45-mm-plus-1-00-mm-11-1-compression-for-polaris-330","title":"NAMURA NA-50025-4K Top End Kit, 79.45 mm Plus 1.00 mm, 11:1 Compression for Polaris 330","description":"\u003cp\u003eRestore top-end performance with the NAMURA NA-50025-4K Top End Kit, designed for select Polaris Trail Blazer 330 and Trail Boss 330 ATV applications. This complete kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit, providing the primary components needed for a reliable top-end rebuild. The kit features a 79.45 mm piston size with a plus 1.00 mm oversize configuration and an 11:1 compression ratio.\u003c\/p\u003e\u003cp\u003eThe NAMURA piston uses a hypereutectic casting process with increased silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. Its MOS2, or Teflon\/molybdenum, coated skirts use a rolled-on application process for a strong bond and help reduce friction, improve heat transfer, and minimize the risk of cold seizures. Machined smooth heads help reflect combustion heat and reduce carbon buildup, while anodized domes improve heat resistance and piston durability.\u003c\/p\u003e\u003cp\u003eThis NAMURA manufacturer part number NA-50025-4K top-end kit fits 2008–2013 Polaris Trail Blazer 330 models and 2003–2006 Polaris Trail Boss 330 models. Verify the vehicle model, year, bore specification, and required oversize before installation. The kit is supplied by the vendor under part number 186-50254 and is intended for applications requiring a plus 1.00 mm top-end piston configuration.\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\u003e79.45 mm piston size with plus 1.00 mm oversize configuration\u003c\/li\u003e\n\u003cli\u003e11:1 compression ratio for compatible Polaris 330 applications\u003c\/li\u003e\n\u003cli\u003eMOS2 Teflon\/molybdenum-coated piston skirts help reduce friction, improve heat transfer, and minimize cold-seizure risk\u003c\/li\u003e\n\u003cli\u003eMachined smooth piston heads help reflect combustion heat and reduce carbon buildup\u003c\/li\u003e\n\u003cli\u003eAnodized piston domes provide increased heat resistance and durability\u003c\/li\u003e\n\u003cli\u003eHypereutectic casting process provides controlled expansion and improved wear resistance\u003c\/li\u003e\n\u003cli\u003eFits 2008–2013 Polaris Trail Blazer 330 and 2003–2006 Polaris Trail Boss 330 models\u003c\/li\u003e\n\u003cli\u003eBrand: NAMURA\u003c\/li\u003e\n\u003cli\u003eManufacturer part number: NA-50025-4K\u003c\/li\u003e\n\u003cli\u003eVendor part number: 186-50254\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n2003 Polaris Magnum 330 2X4\u003cbr\u003e\n2003 Polaris Magnum 330 4X4\u003cbr\u003e\n2003 Polaris Trail Boss 330\u003cbr\u003e\n2004 Polaris Atp 330\u003cbr\u003e\n2004 Polaris Magnum 330 2X4\u003cbr\u003e\n2004 Polaris Magnum 330 4X4\u003cbr\u003e\n2004 Polaris Trail Boss 330\u003cbr\u003e\n2005 Polaris Atp 330\u003cbr\u003e\n2005 Polaris Magnum 330 2X4\u003cbr\u003e\n2005 Polaris Magnum 330 4X4\u003cbr\u003e\n2005 Polaris Trail Boss 330\u003cbr\u003e\n2006 Polaris Magnum 330 4X4\u003cbr\u003e\n2006 Polaris Trail Boss 330\u003cbr\u003e\n2007 Polaris Trail Boss 330\u003cbr\u003e\n2008 Polaris Trail Blazer 330\u003cbr\u003e\n2008 Polaris Trail Boss 330\u003cbr\u003e\n2009 Polaris Trail Blazer 330\u003cbr\u003e\n2009 Polaris Trail Boss 330\u003cbr\u003e\n2010 Polaris Trail Blazer 330\u003cbr\u003e\n2010 Polaris Trail Boss 330\u003cbr\u003e\n2011 Polaris Trail Blazer 330\u003cbr\u003e\n2011 Polaris Trail Boss 330\u003cbr\u003e\n2012 Polaris Trail Blazer 330\u003cbr\u003e\n2012 Polaris Trail Boss 330\u003cbr\u003e\n2013 Polaris Trail Blazer 330\u003cbr\u003e\n2013 Polaris Trail Boss 330","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67558611386603,"sku":"186-50254","price":123.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/dd77-572a583cd9540_7b0bfc54-bc9c-4c36-8494-7491854e6954.jpg?v=1790767920","url":"https:\/\/ctracingservices.com\/products\/namura-na-50025-4k-top-end-kit-79-45-mm-plus-1-00-mm-11-1-compression-for-polaris-330","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}