{"product_id":"athena-p400250100011-big-bore-cylinder-kit-kawasaki-kx125-moto-house-mx","title":"Athena Big Bore Cylinder Kit P400250100011 — Kawasaki KX125 2003-2007","description":"\u003ch1\u003e\u003cstrong\u003eAthena Big Bore Cylinder Kit P400250100011 — Kawasaki KX125 2003-2007\u003c\/strong\u003e\u003c\/h1\u003e\n\u003ch2\u003eProduct Description\u003c\/h2\u003e\n\u003cp\u003eUnlock the hidden potential of your machine with the \u003cstrong\u003eAthena Big Bore Cylinder Kit\u003c\/strong\u003e. Engineered to increase your displacement to a competitive 144cc, this kit is designed for riders who need that extra grunt to clear jumps and dominate the track. By replacing your stock top end with this premium \u003cstrong\u003ealuminum cylinder\u003c\/strong\u003e, you gain significant torque and a wider, more usable powerband, elevating your bike's overall performance to race-winning standards.\u003c\/p\u003e\n\u003cp\u003eThe cylinder features a specialized \u003cstrong\u003enickel carbide coating\u003c\/strong\u003e for superior heat transfer and long-lasting durability, even under the most demanding racing conditions. The kit is comprehensive, including an aluminum cylinder head with a removable bronze dome for optimized combustion efficiency, and a high-performance \u003cstrong\u003eCast Lite piston kit\u003c\/strong\u003e. Athena also includes a full top-end gasket set and custom hard-anodized power valves—specifically engineered for this cylinder's geometry—to ensure perfect reliability and power delivery.\u003c\/p\u003e\n\u003ch3\u003eTop Features: Athena Big Bore Cylinder Kit\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eIncreases displacement to 144cc for enhanced competitive power\u003c\/li\u003e\n\u003cli\u003eLightweight aluminum cylinder with nickel carbide coating for reduced friction\u003c\/li\u003e\n\u003cli\u003eIncludes specialized, high-performance hard anodized power valves\u003c\/li\u003e\n\u003cli\u003eAluminum cylinder head features a removable bronze dome for improved cooling\u003c\/li\u003e\n\u003cli\u003eComprehensive kit includes Cast Lite piston, rings, clips, pin, and top-end gaskets\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003ePlease review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch2\u003eFitment List\u003c\/h2\u003e\n\u003ctable style=\"width: 100%; border-collapse: collapse; border: 1px solid #e0e0e0; margin-top: 15px; margin-bottom: 15px;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #f7f7f7;\"\u003e\n\u003cth style=\"border: 1px solid #e0e0e0; padding: 12px; text-align: left; font-weight: bold; color: #333333;\"\u003eYear Range\u003c\/th\u003e\n\u003cth style=\"border: 1px solid #e0e0e0; padding: 12px; text-align: left; font-weight: bold; color: #333333;\"\u003eVehicle Brand\u003c\/th\u003e\n\u003cth style=\"border: 1px solid #e0e0e0; padding: 12px; text-align: left; font-weight: bold; color: #333333;\"\u003eVehicle Model \u0026amp; Sub-Model\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003e2003-2005\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eKawasaki\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eKX125\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003e2006-2007\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eKawasaki\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eKX125\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Is this a bolt-on kit, or do I need to modify my engine cases?\u003c\/strong\u003e\u003cbr\u003eA: This kit is designed to bolt directly onto your stock engine cases. However, because you are increasing displacement, you will need to re-jet your carburetor to ensure the engine receives the proper air-fuel ratio for the increased size.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Why are the included power valves different from OEM?\u003c\/strong\u003e\u003cbr\u003eA: Athena uses custom-profiled power valves to match the increased port volume and timing of the big bore cylinder. OEM valves are not designed for this specific geometry and will not function correctly with this kit.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eExpert Pro-Tip:\u003c\/strong\u003e After upgrading to 144cc, keep a close eye on your cooling system. A larger displacement creates more heat. Ensure your cooling system is in top shape, use a high-quality coolant, and consider upgrading to a higher-pressure radiator cap if you race in extreme conditions to prevent the engine from reaching dangerous temperatures.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecommended Pairings:\u003c\/strong\u003e\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/kawasaki-kx125-performance-upgrades-engine-mods-and-accessories-moto-house-mx\"\u003eKawasaki KX125 Performance Parts \u0026amp; Upgrades\u003c\/a\u003e\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/premium-motorcycle-chemicals-brake-fluid-bike-wash-coolant-chain-lubes\"\u003ePremium Motorcycle Chemicals\u003c\/a\u003e\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/kawasaki-2-stroke-dirt-bikes-performance-parts-accessories-moto-house-mx\"\u003eKawasaki 2-Stroke Performance Parts\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eAbout Moto-House MX\u003c\/h2\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. Every order ships fast from our Central Florida location.\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eMoto-House MX – Choice of Champions\u003c\/strong\u003e – Clermont \/ Montverde, FL. Central Florida's premier powersports source with lightning-fast worldwide shipping.\u003c\/em\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"Cylinder Works","offers":[{"title":"Default Title","offer_id":39698430951507,"sku":"P400250100011","price":1201.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/athena-cylinder-kit-big-bore-58mm-144cc-kawasaki-kx125-2003-2005-p400250100011-878030.jpg?v=1735340608","url":"https:\/\/motohousemx.com\/products\/athena-p400250100011-big-bore-cylinder-kit-kawasaki-kx125-moto-house-mx","provider":"Moto-House MX","version":"1.0","type":"link"}