{"product_id":"namura-nx-40026k-top-end-kit-for-1992-1994-yamaha-yz250-67-94-mm-standard-bore-11-1-compression","title":"Namura NX-40026K Top End Kit for 1992–1994 Yamaha YZ250, 67.94 mm Standard Bore, 11:1 Compression","description":"\u003cp\u003eRefresh the top end of your two-stroke motorcycle with the Namura NX-40026K Top End Kit. Designed for the standard-bore 1992, 1993, and 1994 Yamaha YZ250, this ceramic competition kit includes the piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit needed for a comprehensive top-end rebuild. The 67.94 mm piston is engineered for an 11:1 compression ratio and dependable performance in demanding riding conditions.\u003c\/p\u003e\u003cp\u003eThe piston uses a hypereutectic casting process with increased silicon content to help control expansion, improve wear resistance, and withstand higher cylinder temperatures. MOS2, or Teflon and molybdenum, coated skirts are applied using a rolled-on process that creates a strong bond while helping reduce friction, improve heat transfer, and minimize the risk of cold seizures. The machined smooth head helps reflect combustion heat and reduce carbon buildup, supporting consistent operation and piston protection.\u003c\/p\u003e\u003cp\u003eAn anodized dome adds heat resistance and durability, while the included rings, wrist pin, clips, bearing, and gasket kit provide the essential components for installation. This Namura top-end kit is manufactured for direct fitment on 1992–1994 Yamaha YZ250 models. Verify the model year, cylinder condition, and required bore specification before installation to ensure proper fit and clearance.\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\u003e67.94 mm standard-bore piston designed for an 11:1 compression ratio\u003c\/li\u003e\n\u003cli\u003eMOS2 Teflon and molybdenum coated skirt helps 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 piston dome improves heat resistance and durability\u003c\/li\u003e\n\u003cli\u003eHypereutectic casting process provides controlled expansion, increased wear resistance, and improved high-temperature performance\u003c\/li\u003e\n\u003cli\u003eFits 1992 Yamaha YZ250, 1993 Yamaha YZ250, and 1994 Yamaha YZ250\u003c\/li\u003e\n\u003cli\u003eBrand: Namura\u003c\/li\u003e\n\u003cli\u003eManufacturer part number: NX-40026K\u003c\/li\u003e\n\u003cli\u003eVendor part number: 185-4026\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n1992 Yamaha YZ250\u003cbr\u003e\n1993 Yamaha YZ250\u003cbr\u003e\n1994 Yamaha YZ250","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67559780221163,"sku":"185-4026","price":120.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/d7f2-5e961d8aa27e8.jpg?v=1790772975","url":"https:\/\/ctracingservices.com\/products\/namura-nx-40026k-top-end-kit-for-1992-1994-yamaha-yz250-67-94-mm-standard-bore-11-1-compression","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}