{"product_id":"58mm-big-bore-kit-144cc","title":"58mm Big Bore Kit 144cc","description":"This kit increases the engine's displacement to 144 cc with a 58 mm bore diameter. The intake and exhaust ports are optimized for gas flow, and cooling chambers are incorporated to prevent overheating during demanding use. Athena guarantees maximum durability and smoothness through a special nickel and silicon treatment of the barrel.\n\nThe kit includes the aluminum cylinder, cylinder head, a complete piston with pin and rings, and all necessary gaskets. The modular cylinder head features an aluminum outer casing and a bronze inner dome, allowing for customization of compression and squish ratios while improving heat dissipation and extending engine life. Athena specifies that when the cylinder kit is disassembled, only specific Athena spare gasket kits should be used; OE replacement gaskets are not to be used.\n\nThis product is designated for Race Use Only and is not intended for street use. All Athena products must be used in compliance with the specific national regulations of the member state where they are marketed or sold. Athena disclaims all responsibility for any improper use.\n\nThe Athena Big Bore Cylinder Kit is compatible with the Yamaha YZ 125 models from 2022 to 2024. Installation requires boring of the engine crankcase.","brand":"Athena","offers":[{"title":"Default Title","offer_id":52687002632504,"sku":"P400485100101","price":827.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/660677144.webp?v=1784879348","url":"https:\/\/store.motormia.co\/products\/58mm-big-bore-kit-144cc","provider":"MOTORMIA","version":"1.0","type":"link"}