{"product_id":"wossner-8302dc-piston-kit-2005-2021-yamaha-yz125-yz125x-standard-size-c","title":"Wossner 8302DC Piston Kit - 2005-2021 Yamaha YZ125 YZ125X Standard Size C","description":"\u003ch3\u003eWossner 8302DC Standard Series Forged 2-Stroke Piston Kit - Standard Size C\u003c\/h3\u003e\n\u003cp\u003eBring the snap and reliability back to your Yamaha small-bore with the Wossner 8302DC Piston Kit. Precision-engineered for the 2005-2021 Yamaha YZ125 and the 2020-2022 YZ125X, the \"Size C\" forged kit is the expert choice for cylinders that have seen high hours of use. At Moto-House MX, we know that after many seasons of wide-open throttle, 125cc cylinder bores naturally expand; this +0.02mm Size C kit provides the precise fitment needed to restore a tight seal and eliminate power loss in worn bores.\u003c\/p\u003e\n\u003cp\u003eForged from high-performance aerospace aluminum alloy, the 8302DC is significantly more durable and heat-resilient than stock cast pistons. It features a dual-ring configuration, offering superior secondary compression and enhanced heat transfer from the piston to the cylinder wall—a vital feature for small-bore engines that operate at the edge of their RPM range. To ensure long-term performance, Wossner applies a permanent molybdenum disulphide skirt coating that reduces friction and prevents piston rock. Precision-machined for 54.02mm bores, this 53.97mm piston kit allows you to extend the life of your Yamaha cylinder before needing a replate.\u003c\/p\u003e\n\u003ch3\u003eTop Features: Wossner 8302DC Piston Kit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eStandard Size C (53.97mm):\u003c\/b\u003e Specifically designed for 54.02mm bores to compensate for moderate cylinder wear and restore factory-level compression.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eDual Ring Design:\u003c\/b\u003e Enhances cylinder sealing and cooling efficiency, maintaining a reliable powerband during long motos or technical off-road loops.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eAerospace-Grade Forging:\u003c\/b\u003e Built to withstand high-RPM stress and mechanical fatigue far better than original cast alternatives.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eLow-Friction Skirt Coating:\u003c\/b\u003e Permanent skirt treatment minimizes internal drag, protects the cylinder wall, and ensures a quieter engine.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eOptimized Lightness:\u003c\/b\u003e Expertly machined to reduce reciprocating mass, ensuring the YZ125 retains its lightning-fast throttle response.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eComplete Assembly:\u003c\/b\u003e Includes the forged Size C piston, performance rings, wrist pin, and circlips.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cb\u003eExpert Pro-Tip:\u003c\/b\u003e The Yamaha YZ125 is a high-performance machine that requires perfect tolerances for peak horsepower. If your cylinder has seen significant use and measures slightly beyond factory Size A or B specs, moving to a Wossner Size C (53.97mm) is the professional way to bring your piston-to-wall clearance back to perfection. Always use a precision bore gauge to confirm your cylinder measures 54.02mm before installation. For a professional-grade rebuild, always install with a fresh top-end gasket kit and utilize premium 2-stroke oil to protect your investment.\u003c\/p\u003e\n\u003ch3\u003eFitment List\u003c\/h3\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse;\" cellpadding=\"8\" border=\"1\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eYear Range\u003c\/th\u003e\n\u003cth\u003eVehicle Brand\u003c\/th\u003e\n\u003cth\u003eVehicle Model\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e2005-2021\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYZ125\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2020-2022\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYZ125X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cb\u003eQ: When should I choose Size C instead of Size A or B?\u003c\/b\u003e\u003cbr\u003eA: Size C (53.97mm) is used when the cylinder bore has worn larger (to 54.02mm) due to high hours. This slightly larger piston restores the tight seal necessary for peak power and prevents \"piston slap.\"\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: Is this kit compatible with the YZ125X off-road model?\u003c\/b\u003e\u003cbr\u003eA: Yes, this kit is fully compatible with both the YZ125 motocross bike and the YZ125X cross-country model within the specified year ranges.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: Do forged pistons last longer than cast ones?\u003c\/b\u003e\u003cbr\u003eA: Generally, yes. The forging process makes the metal denser and much more resistant to the structural fatigue and cracking that can occur with cast pistons in high-performance 2-stroke engines.\u003c\/p\u003e\n\u003ch3\u003eRecommended Pairings\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eComplete Top End Gasket Set:\u003c\/b\u003e Ensure a leak-free rebuild and maintain correct squish heights with fresh gaskets.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eMotul 800 2T Factory Line:\u003c\/b\u003e The ultimate high-performance lubricant to keep your new forged piston protected in racing conditions.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eRestore your machine’s power and precision today. Buy now at Moto-House MX!\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eMoto-House MX – Choice of Champions\u003c\/b\u003e – is located in Clermont\/Montverde, FL. The Best Motocross\/UTV \u0026amp; ATV Shop in Central Florida. Stop by our local store in Montverde, FL or enjoy lightning-fast shipping across the USA.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"WOSSNER","offers":[{"title":"Default Title","offer_id":44495995371603,"sku":"8302DC","price":132.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/2756526.png?v=1776229804","url":"https:\/\/motohousemx.com\/products\/wossner-8302dc-piston-kit-2005-2021-yamaha-yz125-yz125x-standard-size-c","provider":"Moto-House MX","version":"1.0","type":"link"}