{"product_id":"namura-nx-40098k-top-end-kit-for-2019-2021-yamaha-yz85-47-44-mm-0-020-in-ceramic-compression","title":"Namura NX-40098K Top End Kit for 2019-2021 Yamaha YZ85, 47.44 mm (+0.020 in) Ceramic Compression","description":"\u003cp\u003eThe Namura NX-40098K Top End Kit is designed for select 2019, 2020, and 2021 Yamaha YZ85 models. This complete top-end solution includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit for a convenient engine rebuild. With a 47.44 mm (+0.020 inch) piston size and an 11:1 compression ratio, the kit is engineered to support reliable performance and consistent operation in demanding motocross applications.\u003c\/p\u003e\u003cp\u003eThe piston features MOS2, a Teflon and molybdenum coating applied through a rolled-on process that creates a bond substantially stronger than many spray-on coatings. This coating helps improve heat transfer, reduce friction, and minimize the risk of cold seizures. The machined-smooth head helps reflect combustion heat, reduce carbon buildup, and protect the piston crown during operation.\u003c\/p\u003e\u003cp\u003eAn anodized dome improves heat resistance and durability, while the hypereutectic casting process increases silicon content for controlled expansion and enhanced wear resistance. These properties help the piston withstand elevated cylinder temperatures and maintain dependable fitment throughout the engine's operating range. The Namura NX-40098K kit is manufactured for direct fitment on 2019-2021 Yamaha YZ85 motorcycles and is intended for top-end service or replacement applications.\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, clips, top-end bearing, and gasket kit\u003c\/li\u003e\n\u003cli\u003e47.44 mm (+0.020 inch) 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 controlled expansion and improved wear resistance\u003c\/li\u003e\n\u003cli\u003eDirect fitment for 2019, 2020, and 2021 Yamaha YZ85 models\u003c\/li\u003e\n\u003cli\u003eBrand: Namura\u003c\/li\u003e\n\u003cli\u003eManufacturer part number: NX-40098K\u003c\/li\u003e\n\u003cli\u003eVendor part number: 185-4098\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n2019 Yamaha YZ85\u003cbr\u003e\n2020 Yamaha YZ85\u003cbr\u003e\n2021 Yamaha YZ85","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67559692992747,"sku":"185-4098","price":101.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/87df-5e961e977b6e5.jpg?v=1790772805","url":"https:\/\/ctracingservices.com\/products\/namura-nx-40098k-top-end-kit-for-2019-2021-yamaha-yz85-47-44-mm-0-020-in-ceramic-compression","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}