{"product_id":"namura-nx-40001-bk-top-end-kit-for-yamaha-yz125-53-95-mm-bore","title":"Namura NX-40001-BK Top End Kit for Yamaha YZ125, 53.95 mm Bore","description":"\u003cp\u003eThe Namura NX-40001-BK Top End Kit is designed for select Yamaha YZ125 applications and provides the key components needed to restore top-end performance. This kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit for a comprehensive installation. The 53.95 mm piston is engineered with an 11:1 compression ratio and is suitable for replacing worn or damaged top-end components.\u003c\/p\u003e\u003cp\u003eBuilt using Namura's hypereutectic casting process, the piston features increased silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. The MOS2, or Teflon\/Molybdenum, coated skirts use a rolled-on application process that creates a durable 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 reliable piston operation.\u003c\/p\u003e\u003cp\u003eThe anodized dome adds heat resistance and durability for demanding two-stroke riding conditions. This Namura top-end kit is manufactured for dependable fit and function and is a practical choice for engine rebuilding or scheduled maintenance. It fits 2002, 2003, and 2004 Yamaha YZ125 models. Verify the model year, bore specification, and service requirements before installation to ensure compatibility.\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\u003e53.95 mm Bore: Designed for compatible Yamaha YZ125 top-end applications\u003c\/li\u003e\n\u003cli\u003e11:1 Compression Ratio: Supports the specified engine configuration\u003c\/li\u003e\n\u003cli\u003eMOS2-Coated Skirts: 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\u003c\/li\u003e\n\u003cli\u003eAnodized Dome: Increases heat resistance and piston durability\u003c\/li\u003e\n\u003cli\u003eHypereutectic Construction: Provides controlled expansion, wear resistance, and improved high-temperature performance\u003c\/li\u003e\n\u003cli\u003eFitment: Fits 2002, 2003, and 2004 Yamaha YZ125 models\u003c\/li\u003e\n\u003cli\u003eBrand: Namura\u003c\/li\u003e\n\u003cli\u003eManufacturer Part Number: NX-40001-BK\u003c\/li\u003e\n\u003cli\u003eVendor Part Number: 185-4001B\u003c\/li\u003e\n\u003c\/ul\u003e\u003cbr\u003e\nFitment:\u003cbr\u003e\n2002 Yamaha YZ125\u003cbr\u003e\n2003 Yamaha YZ125\u003cbr\u003e\n2004 Yamaha YZ125","brand":"NAMURA","offers":[{"title":"Default Title","offer_id":67559852081387,"sku":"185-4001B","price":102.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/3882\/9547\/files\/a9cd-5d76d54d07f08.jpg?v=1790773153","url":"https:\/\/ctracingservices.com\/products\/namura-nx-40001-bk-top-end-kit-for-yamaha-yz125-53-95-mm-bore","provider":"Cascade Tire \u0026 Racing Services","version":"1.0","type":"link"}