{"product_id":"prox-01-2448-a-piston-kit-yamaha-yz450f-wr450f-yz450fx-moto-house-mx","title":"ProX Piston Kit (96.95mm \/ Size A \/ 12.8:1) 01.2448.A - Yamaha YZ450F \/ WR450F \/ YZ450FX 2018-2020","description":"\u003ch1\u003e\u003cstrong\u003eProX Piston Kit (96.95mm \/ Size A \/ 12.8:1) 01.2448.A - 2018-2019 Yamaha YZ450F - 2018-2020 WR450F \/ YZ450FX\u003c\/strong\u003e\u003c\/h1\u003e\n\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe ProX 01.2448.A Piston Kit is engineered as a precision top-end solution for Yamaha 450cc four-stroke platforms requiring a Standard Size A bore profile. Manufactured from dedicated \u003cstrong\u003ealuminum alloy\u003c\/strong\u003e, this 96.95mm piston assembly matches factory tolerances for running inside a standard 97.00mm cylinder sleeve or plated bore. Designed to maintain the factory 12.8:1 compression ratio, this assembly provides immediate combustion seal and mechanical stability across high-RPM motocross and off-road operating conditions.\u003c\/p\u003e\n\u003cp\u003eEach piston is machined using CNC equipment to ensure uniform skirt geometry, proper ring land dimensions, and accurate pin bore alignment. The included \u003cstrong\u003episton rings\u003c\/strong\u003e are produced in original equipment facilities to strict material specifications, guaranteeing optimal cylinder wall seating and heat transfer. The complete kit includes the piston, ring pack, wrist pin, circlips, and an instruction sheet to service your four-stroke motor during routine top-end maintenance or complete teardowns.\u003c\/p\u003e\n\u003ch3\u003eTop Features: ProX Piston Kit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eManufactured from aluminum alloy and machined on CNC equipment for tight dimensional accuracy.\u003c\/li\u003e\n\u003cli\u003eStandard Size A 96.95mm piston engineered for standard 97.00mm bore cylinder applications.\u003c\/li\u003e\n\u003cli\u003eMaintains the stock 12.8:1 compression ratio across 450cc Yamaha four-stroke engines.\u003c\/li\u003e\n\u003cli\u003eIncludes dedicated piston rings manufactured in OEM facilities to factory specifications.\u003c\/li\u003e\n\u003cli\u003eSupplied as a complete top-end package with piston, ring set, wrist pin, circlips, and instruction sheet.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003ePlease review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.\u003c\/p\u003e\n\u003ch3\u003eFitment List\u003c\/h3\u003e\n\u003ctable border=\"1\" cellpadding=\"5\" style=\"border-collapse: collapse; width: 100%;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #f2f2f2;\"\u003e\n\u003cth\u003eYear Range\u003c\/th\u003e\n\u003cth\u003eVehicle Brand\u003c\/th\u003e\n\u003cth\u003eVehicle Model \u0026amp; Sub-Model\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e2018-2019\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYZ450F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2019-2020\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eWR450F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2019-2020\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYZ450FX\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: What cylinder bore size does this Size A piston require?\u003c\/b\u003e\u003cbr\u003eA: This 96.95mm Size A piston is designed for a standard 97.00mm cylinder bore, providing the specified running clearance for standard cylinder diameters.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: What components are supplied in the ProX kit?\u003c\/b\u003e\u003cbr\u003eA: The kit comes complete with the aluminum alloy piston, piston ring set, wrist pin, a pair of circlips, and an instruction sheet.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eQ: Does this piston change the factory compression ratio on my Yamaha 450?\u003c\/b\u003e\u003cbr\u003eA: No, this assembly maintains the factory-specified 12.8:1 compression ratio.\u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eExpert Pro-Tip:\u003c\/b\u003e Before installing any four-stroke piston into a plated cylinder, always check your ring end gap by squaring each ring in the cylinder bore about an inch down using the piston crown. Use a feeler gauge to verify gap clearance according to the included ProX instruction sheet. When seating the wrist pin circlips, ensure the open gap points downward toward the 6 o'clock position (or upward at 12 o'clock), never inline with the pin thrust motion, and double-check that the clip is fully seated inside its groove before cylinder installation.\u003c\/p\u003e\n\u003ch3\u003eRecommended Pairings:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/motohousemx.com\/collections\/yamaha-yz450f-performance-upgrades-engine-mods-and-accessories-moto-house-mx\"\u003eYamaha YZ450F Performance Parts \u0026amp; Upgrades\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/motohousemx.com\/collections\/yamaha-4-stroke-dirt-bikes-performance-parts-accessories-moto-house-mx\"\u003eYamaha 4-Stroke Performance Parts\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/motohousemx.com\/collections\/mx-off-road-motorcycle-tools\"\u003eMotorcycle Tools Performance Parts \u0026amp; Upgrades\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAt Moto-House MX, we carry the best brands in motocross and off-road performance. Our team has over 40 years of experience helping riders get more out of their bikes. We pride ourselves on great customer service, and every item ships FAST - straight to your door.\u003c\/p\u003e\n\u003cp\u003e\u003ci\u003e\u003cstrong\u003eMoto-House MX - Choice of Champions\u003c\/strong\u003e - Your premier powersports source with great customer service and lightning-fast shipping straight to your door.\u003c\/i\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"ProX","offers":[{"title":"96.95 A. \/ STD 12.8:1 YAM \/ 2018-2019","offer_id":39332156178515,"sku":"01.2448.A","price":191.96,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/pro-x-piston-forged-kit-2018-2019-yamaha-yz450f-yz450fx-and-wr450f-486959.jpg?v=1735459747","url":"https:\/\/motohousemx.com\/products\/prox-01-2448-a-piston-kit-yamaha-yz450f-wr450f-yz450fx-moto-house-mx","provider":"Moto-House MX","version":"1.0","type":"link"}