{"product_id":"wossner-8330dc-piston-kit-47-47-mm-for-yamaha-motorcycles-2000-2023","title":"Wossner 8330DC Piston Kit - 2002-2026 Yamaha YZ85 Standard Size C","description":"\u003ch3\u003eWossner 8330DC Standard Series Forged 2-Stroke Piston Kit - Standard Size C\u003c\/h3\u003e\n\u003cp\u003eMaximize the lifespan of your racing cylinder with the Wossner 8330DC Piston Kit. Designed specifically for the 2002-2026 Yamaha YZ85, the \"Size C\" piston is the professional solution for engines that have undergone extensive track use. At Moto-House MX, we know that 85cc cylinders naturally expand over time; this +0.02mm Size C kit is engineered to provide the exact piston-to-wall clearance required to restore lost compression and eliminate power-robbing piston rock in worn bores.\u003c\/p\u003e\n\u003cp\u003eForged from premium aerospace-grade aluminum alloy, the 8330DC offers the structural integrity needed for high-RPM 2-stroke competition. This kit features a dual-ring configuration, which provides a broader powerband and superior heat dissipation—critical for keeping mini-moto engines cool during long motos. Wossner’s permanent molybdenum disulphide skirt coating reduces internal friction, while optimized machining ensures the piston remains lightweight for lightning-fast throttle response. This 47.47mm piston is precision-matched for 47.52mm bores, allowing you to get more hours out of your YZ85 cylinder before requiring a costly replate.\u003c\/p\u003e\n\u003ch3\u003eTop Features: Wossner 8330DC Piston Kit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cb\u003eStandard Size C (47.47mm):\u003c\/b\u003e Precision-engineered for 47.52mm bores, providing the perfect fit for cylinders with moderate wear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eDual Ring Design:\u003c\/b\u003e Enhances cylinder sealing and cooling efficiency for consistent power delivery under racing conditions.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eAerospace-Grade Forged Construction:\u003c\/b\u003e Denser and stronger than stock cast pistons, offering maximum resistance to fatigue and thermal stress.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eLow-Friction Skirt Coating:\u003c\/b\u003e Permanent skirt coating protects the cylinder wall and ensures a smooth break-in and quieter operation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eOptimized Strength-to-Weight:\u003c\/b\u003e Machined to minimize reciprocating mass for rapid acceleration while maintaining strength in the crown and skirt.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eComplete Top-End 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 In the world of 85cc racing, precision is everything. As your YZ85 cylinder wears past the limits of a Size A or B piston, the Wossner Size C (47.47mm) is the go-to choice for top-level mechanics to restore mechanical tolerances. Always use a precision bore gauge to confirm your cylinder measures 47.52mm before installation. To ensure professional results, always install with a fresh top-end gasket kit and utilize high-quality 2-stroke premix oil to protect your newly rebuilt top end.\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\u003e2002-2026\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYZ85 \/ YZ85LW (Large Wheel)\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 is it time to move to a Size C piston?\u003c\/b\u003e\u003cbr\u003eA: You should move to a Size C (47.47mm) when your cylinder has worn beyond the specifications for Size A or B. If your bore measures approximately 47.52mm, the Size C will bring your clearances back to the ideal range for peak performance.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: Does this forged piston fit the Large Wheel (LW) model?\u003c\/b\u003e\u003cbr\u003eA: Yes, the 8330DC fits all Yamaha YZ85 engine platforms from 2002 to 2026, including the standard and Large Wheel versions.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: What are the benefits of the dual-ring design?\u003c\/b\u003e\u003cbr\u003eA: The dual-ring setup on the YZ85 provides better heat transfer to the cylinder and more consistent compression across the RPM range compared to a single-ring design, making it more durable for non-professional racers.\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 Required to ensure a proper seal and maintain correct squish heights.\u003c\/li\u003e\n\u003cli\u003e\n\u003cb\u003eYamalube 2-R Premix Oil:\u003c\/b\u003e The ultimate protection for Yamaha’s high-revving 2-stroke racing engines.\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":44495997927507,"sku":"8330DC","price":122.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/2756519.png?v=1776229900","url":"https:\/\/motohousemx.com\/products\/wossner-8330dc-piston-kit-47-47-mm-for-yamaha-motorcycles-2000-2023","provider":"Moto-House MX","version":"1.0","type":"link"}