{"product_id":"4649m09200-wiseco-std-piston-kit-for-yamaha-yz400f-wr400f-1998-2000-92mm-12-5-1","title":"4649M09200 Wiseco Std Piston Kit for Yamaha YZ400F WR400F 1998-2000 92mm 12.5:1","description":"\u003ch2\u003eWiseco Std Piston Kit for Yamaha YZ400F\/WR400F\u003c\/h2\u003e\u003cp\u003eThis Wiseco Standard Piston Kit for Yamaha YZ400F and WR400F models delivers a 92mm bore at a 12.5:1 compression ratio, with the 4649M09200 part number serving as the OEM cross-reference for this standard replacement piston.\u003c\/p\u003e\u003ch4\u003eOverview\u003c\/h4\u003e\u003cp\u003eThis Wiseco Standard Piston Kit is a direct-fit engine rebuild component for Yamaha YZ400F and WR400F models from 1998 through 2000. The 92mm piston restores factory bore and compression at 12.5:1, making it the correct choice for a top-end refresh or rebuild. Riders and mechanics who need dependable OEM-spec replacement geometry will find this Wiseco piston kit matched to the original specifications.\u003c\/p\u003e\u003ch4\u003eBuilt For Performance\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e92mm standard bore diameter matching original cylinder dimensions\u003c\/li\u003e\n\u003cli\u003e12.5:1 compression ratio for factory-equivalent combustion performance\u003c\/li\u003e\n\u003cli\u003eWiseco forged piston construction for strength under high-rpm loads\u003c\/li\u003e\n\u003cli\u003ePart number 4649M09200 provides a verified OEM cross-reference\u003c\/li\u003e\n\u003cli\u003ePiston kit includes piston, rings, pin, and clips for a complete top-end install\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eFits These Machines\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003efor Yamaha YZ400F, 1998-2000\u003c\/li\u003e\n\u003cli\u003efor Yamaha WR400F, 1998-2000\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eOn-The-Job Use\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eTop-end rebuilds on YZ400F motocross bikes\u003c\/li\u003e\n\u003cli\u003eTrail and enduro service on WR400F models\u003c\/li\u003e\n\u003cli\u003eRoutine piston replacement at scheduled service intervals\u003c\/li\u003e\n\u003cli\u003eRestoration of a worn or scored cylinder bore back to standard size\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\u003e4649M09200\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBore Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e92mm (Standard)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCompression Ratio\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e12.5:1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eWiseco\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFitment Years\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1998-2000\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 Does this piston kit require any cylinder machining? \u003cstrong\u003eA:\u003c\/strong\u003e No, the 92mm standard bore matches the original cylinder size, so it drops in without boring or honing to a larger dimension. Measure your cylinder for wear before installation to confirm it is within service limits.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ:\u003c\/strong\u003e What compression does this kit produce compared to the stock piston? \u003cstrong\u003eA:\u003c\/strong\u003e This kit runs a 12.5:1 compression ratio, which matches the original factory specification for the YZ400F and WR400F. Verify your head and valve condition before assembly to avoid detonation issues.\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":51139967975510,"sku":"OO1C22366","price":483.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0697\/8460\/0662\/files\/s-l1600_69ddc20c-f0ed-42e9-bfa1-0441d8e1772e.jpg?v=1794565862","url":"https:\/\/www.solidspare.com\/products\/4649m09200-wiseco-std-piston-kit-for-yamaha-yz400f-wr400f-1998-2000-92mm-12-5-1","provider":"Solid Spare","version":"1.0","type":"link"}