{"product_id":"vertex-23941b-forged-replica-piston-kit-yamaha-yz250f-moto-house-mx","title":"Vertex Forged  Piston Kit 23941B — Yamaha YZ250F \/ YZ250FX \/ WR250F 2014-2017","description":"\u003ch1\u003e\u003cstrong\u003eVertex Forged Replica Piston Kit 23941B — Yamaha YZ250F \/ YZ250FX \/ WR250F 2014-2017 \u003c\/strong\u003e\u003c\/h1\u003e\n\u003ch4\u003eCompression Ratio 13.5:1\u003c\/h4\u003e\n\u003ch2\u003eProduct Description\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eNote: This premium engine kit includes 1 Forged Piston, 1 Performance Ring Set, 1 Heavy-Duty Wrist Pin, and 2 Retaining Circlips.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBring your high-RPM four-stroke back to peak competitive performance with the Vertex Forged Replica Piston Kit. When your engine stacks up track hours, cylinder and piston wall clearances naturally widen, causing compression loss and power drop. This precision-engineered B-selection (76.96mm) kit delivers a \u003cstrong\u003ehigh-performance top end replacement\u003c\/strong\u003e, manufactured out of premium forged 2618 aluminum alloy to perfectly handle the blistering cylinder pressures and extreme thermal stresses of modern Yamaha 250cc racing setups.\u003c\/p\u003e\n\u003cp\u003eEvery Vertex replica piston is structurally enhanced through an advanced T-5 hardening and tempering treatment cycle to ensure unparalleled crown stability and skirt strength. The piston skirt is subsequently shielded with a high-tech Molybdenum Disulphite coating, which works to dramatically decrease friction during initial engine startup, shorten critical break-in intervals, and increase overall component service life. Built to strict factory specifications, this standard bore, high-compression forged setup optimizes combustion efficiency to maintain crisp throttle response throughout your entire rev range.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eTop Features: Vertex Forged Replica Piston Kit\u003c\/strong\u003e\u003cbr\u003eo Forged from ultra-durable 2618 aluminum alloy and heat-treated with a T-5 hardening cycle.\u003cbr\u003eo Molybdenum Disulphite coated piston skirt lowers friction and accelerates critical engine break-in.\u003cbr\u003eo Precision B-size profile (76.96mm) engineered to restore optimal factory cylinder wall clearances.\u003cbr\u003eo Supplied as a complete, drop-in assembly package containing the piston, premium rings, wrist pin, and circlips.\u003c\/p\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\u003e\n\u003ctbody\u003e\n\u003ctr\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\u003ctr\u003e\n\u003ctd\u003e2014-2015\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYZ250F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2015-2016\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eYZ250FX\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2015-2017\u003c\/td\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eWR250F\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: What does the \"B\" designation in the 23941B part number mean?\u003c\/strong\u003e\u003cbr\u003eA: A \"B\" piston is sized exactly to 76.96mm, which is structurally 0.01mm larger than an \"A\" size stock piston. This tiny increase accounts for normal microscopic cylinder wear over time, restoring proper factory clearances and sealing tight inside your standard 77.00mm bore cylinder.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Is this forged piston heavier or stronger than a stock cast piston?\u003c\/strong\u003e\u003cbr\u003eA: It is substantially stronger. Forged 2618 aluminum features a condensed grain structure that resists fracturing and cracking at high RPM far better than basic cast pistons, allowing it to withstand high heat and heavy off-road loads with ease.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Do I need to measure my old cylinder before dropping this B-piston in?\u003c\/strong\u003e\u003cbr\u003eA: Yes, standard industry procedure is to always check your cylinder roundness and bore size with a dial bore gauge during tear-down. Ensure your cylinder walls still have clean cross-hatching and meet the recommended target piston-to-wall clearances outlined in your factory workshop manual.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eExpert Pro-Tip:\u003c\/strong\u003e Ring end gap alignment is where many mechanics make a devastating mistake. Never put a fresh set of rings into your top end without first sliding the naked top ring down into the cylinder bore using the piston to square it up, then checking the end gap with a feeler gauge. If the gap is too tight, heat expansion can cause the ring tips to butt together, snapping the ring and destroying your fresh cylinder. Additionally, when dropping the circlips into the piston pin tunnel, always orient the open end of the clip straight down (6 o'clock position) or straight up (12 o'clock position) to prevent inertia from compressing and throwing the clip out at 14,000 RPM.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecommended Pairings:\u003c\/strong\u003e\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/yamaha-yz250f-yz250fx-performance-parts-and-accessories\"\u003eYamaha YZ250F \/ YZ250FX Performance Parts \u0026amp; Upgrades\u003c\/a\u003e\u003cbr\u003eo \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\u003cbr\u003eo \u003ca href=\"https:\/\/motohousemx.com\/collections\/premium-motorcycle-chemicals-brake-fluid-bike-wash-coolant-chain-lubes\"\u003ePremium Motorcycle Oils \u0026amp; Assembly Lubes\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":"Moto-House MX","offers":[{"title":"Default Title","offer_id":45799074365523,"sku":"23941B","price":207.86,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1754\/5421\/files\/23941B_1.jpg?v=1783551883","url":"https:\/\/motohousemx.com\/products\/vertex-23941b-forged-replica-piston-kit-yamaha-yz250f-moto-house-mx","provider":"Moto-House MX","version":"1.0","type":"link"}