{"product_id":"wossner-8217da-1999-2026-yamaha-yz250-yz250x-66-35mm-forged-2-stroke-piston-kit","title":"WOSSNER 8217DA 1999-2026 Yamaha YZ250 YZ250X 66.35mm Forged 2-Stroke Piston Kit","description":"\u003cdiv\u003e\n\u003ch3\u003eDitch the stock cast tolerances and give your YZ250 the forged durability it needs to actually stay together when the gate drops.\u003c\/h3\u003e\n\u003cp\u003eIf you're serious about your 250cc power plant, you know that cast pistons are the weak link when the RPMs climb. This Wossner Forged Piston Kit is the mechanical solution for the 1999-2026 Yamaha YZ250 and YZ250X, offering a massive leap in structural integrity over standard parts. Forged from aerospace-grade aluminum alloy, this kit is designed to maintain consistent compression and eliminate the \"soft\" throttle response that comes with worn-out top ends. It delivers Factory Quality fitment that ensures your Yamaha stays crisp through the entire powerband, moto after moto.\u003c\/p\u003e\n\u003cp\u003eThe technical advantage here is Wossner’s single-ring design and permanent skirt coating. By reducing internal friction and piston rock, this kit minimizes drag and heat buildup—the two biggest enemies of a high-performance 2-stroke. This isn't just a replacement part; it’s a hardware upgrade that provides a more stable piston path and better ring seal. Whether you’re wide open on a moto track or lugging through the woods on a YZ250X, this forged setup provides the reliability required for riders who don't have time for a DNF.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAerospace Forged Alloy:\u003c\/strong\u003e Significantly higher tensile strength than cast pistons to prevent skirt collapse.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePermanent Skirt Coating:\u003c\/strong\u003e Reduces friction and protects the cylinder bore during high-load operation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision Single-Ring Design:\u003c\/strong\u003e Engineered for reduced drag and immediate throttle response at high RPM.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMachined for Strength:\u003c\/strong\u003e Lightened architecture that reinforces critical stress points in the crown and skirt wall.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull Rebuild Components:\u003c\/strong\u003e Comes with the 8217DA piston, high-performance ring set, wrist pin, and clips.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cblockquote\u003e\n\u003cstrong\u003eExpert Pro-Tip:\u003c\/strong\u003e Don't just slap this in. Measure your ring end gap and check your cylinder bore to ensure the 66.35mm Size A provides the correct clearance. Always perform three progressive heat cycles before you pin it, and never reuse an old needle bearing when installing a forged piston.\u003c\/blockquote\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; margin: 20px 0;\"\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth style=\"border: 1px solid #dddddd; text-align: left; padding: 10px;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"border: 1px solid #dddddd; text-align: left; padding: 10px;\"\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003eFitment\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003e1999-2026 Yamaha YZ250 \/ YZ250X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003ePiston Size\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003e66.35 mm (Standard Size A)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003eMaterial\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003eForged Aluminum Alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003ePiston Type\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003eSingle Ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003eBore Size\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #dddddd; padding: 10px;\"\u003e66.40 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch4\u003eFrequently Asked Questions\u003c\/h4\u003e\n\u003cp\u003e\u003cstrong\u003eIs this a direct replacement for the OEM Yamaha piston?\u003c\/strong\u003e\u003cbr\u003eYes, it is designed to replace the stock piston but offers the added strength of a forged aluminum alloy construction.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat comes in the 8217DA kit?\u003c\/strong\u003e\u003cbr\u003eThe kit is complete with the piston (#8217DA), a performance ring set (#RSB6640), wrist pin (#WP033), and heavy-duty retaining clips (#CW18).\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill this work with the YZ250X cross-country model?\u003c\/strong\u003e\u003cbr\u003eAbsolutely. This kit is compatible with all 250cc 2-stroke Yamaha engines from 1999 through the 2026 model year, including the X version.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecommended Pairings:\u003c\/strong\u003e\u003cbr\u003eCometic Top-End Gasket Set, Yamaha OEM Needle Bearing, and Premium 2-Stroke Pre-mix Oil.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eMoto-House MX – Choice of Champions\u003c\/b\u003e – is located in Clermont\/Montverde, FL. We are the best motocross shop in Central Florida with lightning-fast shipping.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"WOSSNER","offers":[{"title":"Default Title","offer_id":44496004644947,"sku":"8217DA","price":182.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/2756529.png?v=1776230505","url":"https:\/\/motohousemx.com\/products\/wossner-8217da-1999-2026-yamaha-yz250-yz250x-66-35mm-forged-2-stroke-piston-kit","provider":"Moto-House MX","version":"1.0","type":"link"}