{"product_id":"namura-020-over-bore-piston-kit-size-c-47-46mm-for-yamaha-1993-01-yz80-47-5mm","title":"Namura .020 Over Bore Piston Kit Size C (47.46mm) for Yamaha 1993-01 YZ80 47.5mm","description":"\u003ch2\u003ePiston Kit Size C (47.46mm) .020 Over Bore for Yamaha\u003c\/h2\u003e\u003cp\u003eThis Namura .020 over bore piston kit size C (47.46mm) is a precision oversized piston assembly for Yamaha YZ80 models from 1993 to 2001, designed to restore cylinder compression after a 0.5mm overbore to 47.5mm.\u003c\/p\u003e\u003ch4\u003eOverview\u003c\/h4\u003e\u003cp\u003eThis Namura .020 over bore piston kit size C (47.46mm) provides the next oversize option for Yamaha YZ80 engines needing a fresh bore to 47.5mm. Including a piston, rings, wrist pin, and circlips, the kit allows riders to extend engine life and maintain peak performance. It is a dependable choice for racers and enthusiasts rebuilding the YZ80 top end.\u003c\/p\u003e\u003ch4\u003eBuilt For Performance\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eCast from high‑silicon aluminum for thermal stability and reduced expansion\u003c\/li\u003e\n\u003cli\u003eRing lands are machined to tight tolerances for optimal gas sealing\u003c\/li\u003e\n\u003cli\u003eWrist pin features a phosphate coating for reduced wear\u003c\/li\u003e\n\u003cli\u003eCirclips are chamfered to ease installation and prevent dislodging\u003c\/li\u003e\n\u003cli\u003eEach piston is weight‑matched within the set for smooth operation\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eFits These Machines\u003c\/h4\u003e\u003cul\u003e\u003cli\u003efor Yamaha YZ80 (1993‑2001)\u003c\/li\u003e\u003c\/ul\u003e\u003ch4\u003eOn‑The‑Job Use\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eEngine rebuilds after cylinder wear requires oversize pistons\u003c\/li\u003e\n\u003cli\u003eMotocross competition where consistent power delivery is critical\u003c\/li\u003e\n\u003cli\u003eTrail riding with high‑hour engines needing a larger bore refresh\u003c\/li\u003e\n\u003cli\u003eRestoration of classic Yamaha YZ80 models\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eSpecs At A Glance\u003c\/h4\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003ePart Number(s)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eSize C (47.46mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBore Diameter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e47.46mm (+0.020 over stock)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOverbore Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e0.5mm (0.020 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eHigh‑silicon aluminum alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch4\u003eGood To Know\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eQ:\u003c\/strong\u003e Do I need to hone the cylinder before installing this piston? \u003cstrong\u003eA:\u003c\/strong\u003e Yes, the cylinder must be professionally bored and honed to 47.5mm to match the 47.46mm piston, leaving proper clearance for expansion.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ:\u003c\/strong\u003e Are the rings pre‑gapped for this size? \u003cstrong\u003eA:\u003c\/strong\u003e Rings are not pre‑gapped; you must measure and file the end gaps per the service manual for the Yamaha YZ80 to avoid seizure.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eSlight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.\u003c\/em\u003e\u003c\/p\u003e","brand":"Solid Spare","offers":[{"title":"Default Title","offer_id":44890359562326,"sku":"SZ1F10374","price":104.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0697\/8460\/0662\/files\/1_18d3851f-7748-4de9-bd94-3ee5d01c5c64.jpg?v=1781138299","url":"https:\/\/www.solidspare.com\/products\/namura-020-over-bore-piston-kit-size-c-47-46mm-for-yamaha-1993-01-yz80-47-5mm","provider":"Solid Spare","version":"1.0","type":"link"}