{"product_id":"hot-rods-4138-crankshaft-assembly-yamaha-yz250-moto-house-mx","title":"Hot Rods Crankshaft Assembly 4138 — Yamaha YZ250 \/ YZ250X 2003-2025","description":"\u003ch1\u003e\u003cstrong\u003eHot Rods Crankshaft Assembly 4138 — Yamaha YZ250 \/ YZ250X 2003-2025\u003c\/strong\u003e\u003c\/h1\u003e\n\u003ch2\u003eProduct Description\u003c\/h2\u003e\n\u003cp\u003eKeep your legendary Yamaha 2-stroke running at its best with the \u003cstrong\u003eHot Rods 4138 Crankshaft Assembly\u003c\/strong\u003e. Engineered specifically for the YZ250 and YZ250X, this crankshaft is the industry standard for riders looking to restore factory-fresh performance to their bottom end without the hassle of manual assembly and truing.\u003c\/p\u003e\n\u003cp\u003eForged from high-grade \u003cstrong\u003e4140 steel\u003c\/strong\u003e, this crankshaft is built to handle the explosive power of 2-stroke racing. It comes pre-assembled and factory-trued to exceed OEM specifications, featuring proven Hot Rods connecting rods and top-end bearings. With precision-machined gears rated at DIN class 9 or higher, this unit is built for durability and is fully rebuildable, ensuring it remains a reliable part of your bike's engine for years to come.\u003c\/p\u003e\n\u003ch3\u003eTop Features: Hot Rods Crankshaft Assembly\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSold complete with proven Hot Rods connecting rods and top-end bearings\u003c\/li\u003e\n\u003cli\u003eFactory assembled and trued to meet or exceed OEM specifications\u003c\/li\u003e\n\u003cli\u003eHeavy-duty 4140 steel construction tailored for 2-stroke performance\u003c\/li\u003e\n\u003cli\u003eGears precision-machined to DIN class 9 quality level or higher\u003c\/li\u003e\n\u003cli\u003eComplete, pre-balanced, and ready for immediate installation\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;\"\u003e2003-2025\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eYamaha\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eYZ250\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;\"\u003e2016-2025\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eYamaha\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #e0e0e0; padding: 10px; color: #555555;\"\u003eYZ250X\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 crankshaft assembly a direct drop-in replacement?\u003c\/strong\u003e\u003cbr\u003eA: Yes, it is designed as a direct OEM replacement. Because it is factory-trued, you do not need any special machining to install it in your cases.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Should I use my old crankshaft seals with this assembly?\u003c\/strong\u003e\u003cbr\u003eA: Absolutely not. Always install brand new crankshaft seals when replacing your crank assembly to ensure proper crankcase pressure and prevent air leaks, which can lead to a lean condition and engine failure.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eExpert Pro-Tip:\u003c\/strong\u003e Since you are opening the cases, take the time to inspect the crankcase sealing surfaces for any nicks or scratches. Even a tiny imperfection can ruin your crank seals, so clean everything thoroughly with a high-quality solvent before assembly.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecommended Pairings:\u003c\/strong\u003e\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/yamaha-2-stroke-dirt-bikes-performance-parts-accessories-moto-house-mx\"\u003eYamaha 2-Stroke Performance Parts\u003c\/a\u003e\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/yamaha-yz250-and-yz250x-performance-parts-collection-at-moto-house-mx\"\u003eYamaha YZ250 \/ YZ250X Performance Parts\u003c\/a\u003e\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/premium-motorcycle-chemicals-brake-fluid-bike-wash-coolant-chain-lubes\"\u003eAssembly Lube, Crank Seals, \u0026amp; Chemicals\u003c\/a\u003e\u003c\/p\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":"Hot Rods","offers":[{"title":"Default Title","offer_id":40562244091987,"sku":"4138","price":430.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/hot-rods-oem-replacement-crankshaft-4138-2003-2023-yamaha-yz250yz250x-791637.jpg?v=1735344473","url":"https:\/\/motohousemx.com\/products\/hot-rods-4138-crankshaft-assembly-yamaha-yz250-moto-house-mx","provider":"Moto-House MX","version":"1.0","type":"link"}