{"product_id":"yoshimura-rs-12-stainless-full-exhaust-for-kawasaki-kx250f-x-242950s521","title":"Yoshimura RS-12 Stainless Full Exhaust for Kawasaki KX250F\/X – 242950S521","description":"\u003cdiv class=\"trd trd--yoshimura\"\u003e\n\u003csection class=\"trd-hero\"\u003e\u003cp class=\"trd-eyebrow\"\u003eYoshimura · RS-12 · Full System\u003c\/p\u003e\n\u003ch2 class=\"trd-headline\"\u003eRS-12 Full System for KX250F and KX250X\u003c\/h2\u003e\n\u003cp class=\"trd-lead\"\u003eThe Yoshimura RS-12 Signature Series Full System is a stainless full exhaust system built for the Kawasaki KX250F 2025–2026 and Kawasaki KX250X 2025–2026. Developed around the latest KX250F chassis and engine package, this system is designed to sharpen rider connectivity and deliver stronger output across the power spectrum.\u003c\/p\u003e\n\u003cp class=\"trd-lead\"\u003eIt ships with the INS-31-K sound insert installed, chosen by Yoshimura for an ear-pleasing exhaust note and the best power on this application. For riders who head off the track, an SA-21-K spark arrester is also available separately; see the fitment and insert\/arrester information on the page for details.\u003c\/p\u003e\n\u003cul class=\"trd-chips\"\u003e\n\u003cli class=\"trd-chip\"\u003e\n\u003cspan class=\"trd-chip-label\"\u003ePart Number\u003c\/span\u003e\u003cspan class=\"trd-chip-value\"\u003e242950S521\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"trd-chip\"\u003e\n\u003cspan class=\"trd-chip-label\"\u003eMaterial\u003c\/span\u003e\u003cspan class=\"trd-chip-value\"\u003eStainless\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"trd-chip\"\u003e\n\u003cspan class=\"trd-chip-label\"\u003eSeries\u003c\/span\u003e\u003cspan class=\"trd-chip-value\"\u003eRS-12\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"trd-chip\"\u003e\n\u003cspan class=\"trd-chip-label\"\u003eFits\u003c\/span\u003e\u003cspan class=\"trd-chip-value\"\u003eKawasaki KX250F \/ KX250X\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/section\u003e\u003cdiv class=\"trd-cards trd-cards--3\"\u003e\n\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003cp class=\"trd-label\"\u003eMaterials\u003c\/p\u003e\n\u003ch3 class=\"trd-card-title\"\u003eCarbon Faced Joint\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eYoshimura’s Carbon Faced Machined Joint is designed to eliminate the need for anti-seize. By impregnating the surface of the stainless steel joint with carbon atoms, friction is reduced to help decrease wear over the life of the joint, supporting consistent fit and long-term serviceability.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003cp class=\"trd-label\"\u003eTechnology\u003c\/p\u003e\n\u003ch3 class=\"trd-card-title\"\u003eHeader Resonator Design\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eAn integrated header resonator is engineered for more than appearance. Yoshimura uses this feature to help maximize power across the spectrum while enhancing rider connectivity, contributing to a more usable, responsive feel through the bottom, mid, and top of the rev range.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003cp class=\"trd-label\"\u003eIncluded\u003c\/p\u003e\n\u003ch3 class=\"trd-card-title\"\u003eINS-31-K Included\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eThis RS-12 system comes with the INS-31-K sound insert installed. Yoshimura selected it to produce an ear-pleasing exhaust note and to deliver the best power for the new Kawasaki KX250F application, making it a ready-to-run setup right out of the box.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003csection class=\"trd-story trd-story--text\"\u003e\u003cdiv class=\"trd-story-copy\"\u003e\n\u003cp class=\"trd-label\"\u003ePerformance\u003c\/p\u003e\n\u003ch3 class=\"trd-story-title\"\u003eBuilt Around the New KX\u003c\/h3\u003e\n\u003cp class=\"trd-story-text\"\u003eWith the latest KX250F featuring a new chassis and engine package, Yoshimura developed the RS-12 specifically to add performance to the updated platform. As a Signature Series Exhaust System, it’s positioned as a focused, application-specific full system for riders who want a more connected feel across the powerband on the 2025–2026 KX250F and KX250X.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"trd-story trd-story--text\"\u003e\u003cdiv class=\"trd-story-copy\"\u003e\n\u003cp class=\"trd-label\"\u003eEngineering\u003c\/p\u003e\n\u003ch3 class=\"trd-story-title\"\u003eManufacturer-Reported Output Gains\u003c\/h3\u003e\n\u003cp class=\"trd-story-text\"\u003eYoshimura reports verified gains of “up to 3.3% more HP at 11” and “up to 3.4% more torque at 10” with this RS-12 full system. Combined with the system’s development notes, the goal is added strength up top along with improved connectivity through the bottom and mid portions of the power spectrum.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"trd-story trd-story--text\"\u003e\u003cdiv class=\"trd-story-copy\"\u003e\n\u003cp class=\"trd-label\"\u003eSound\u003c\/p\u003e\n\u003ch3 class=\"trd-story-title\"\u003eInsert and Arrester Options\u003c\/h3\u003e\n\u003cp class=\"trd-story-text\"\u003eThe system is supplied with an INS-31-K sound insert installed, and additional options are offered for tuning sound and use-case preferences. An INS-39-K sound insert is available separately, and the SA-21-K spark arrester is also available separately for riders who plan to venture into the woods. Refer to the sound insert and spark arrester table shown on the page for the available codes and what’s included.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--performance\"\u003e\u003ch2 class=\"trd-section-title\"\u003ePerformance\u003c\/h2\u003e\n\u003cul class=\"trd-stats\"\u003e\n\u003cli class=\"trd-stat\"\u003eUp to 3.3% more HP at 11\u003c\/li\u003e\n\u003cli class=\"trd-stat\"\u003eUp to 3.4% more torque at 10\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"trd-caption\"\u003eFigures as reported by Yoshimura.\u003c\/p\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--video\"\u003e\u003ch2 class=\"trd-section-title\"\u003eProduct Video\u003c\/h2\u003e\n\u003cdiv class=\"trd-video\"\u003e\u003ciframe src=\"https:\/\/www.youtube.com\/embed\/LkWSdyrUhRM\" title=\"Yoshimura RS-12 Stainless Full Exhaust for Kawasaki KX250F\/X – 242950S521 video\" loading=\"lazy\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen\u003e\u003c\/iframe\u003e\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--specs\"\u003e\u003ch2 class=\"trd-section-title\"\u003eSpecifications\u003c\/h2\u003e\n\u003cdiv class=\"trd-table-wrap\"\u003e\u003ctable class=\"trd-table trd-table--specs\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003ePart Number\u003c\/th\u003e\n\u003ctd\u003e242950S521\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eYoshimura\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eProduct Line\u003c\/th\u003e\n\u003ctd\u003eSignature Series Exhaust System\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSeries\u003c\/th\u003e\n\u003ctd\u003eRS-12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSystem Type\u003c\/th\u003e\n\u003ctd\u003eFull System\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eStainless\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSound Insert (Included)\u003c\/th\u003e\n\u003ctd\u003eINS-31-K\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSpark Arrester\u003c\/th\u003e\n\u003ctd\u003eNot included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eShipping Weight\u003c\/th\u003e\n\u003ctd\u003e18 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBarcode\u003c\/th\u003e\n\u003ctd\u003e00840025919976\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eEmissions Compliance\u003c\/th\u003e\n\u003ctd\u003eQUALIFIED MANUFACTURER DECLARED \"REPLACEMENT PART\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--fitment\"\u003e\u003ch2 class=\"trd-section-title\"\u003eFitment\u003c\/h2\u003e\n\u003cdiv class=\"trd-table-wrap\"\u003e\u003ctable class=\"trd-table\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth scope=\"col\"\u003eMake\u003c\/th\u003e\n\u003cth scope=\"col\"\u003eModel\u003c\/th\u003e\n\u003cth scope=\"col\"\u003eModel Years\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eKawasaki\u003c\/td\u003e\n\u003ctd\u003eKX250F\u003c\/td\u003e\n\u003ctd\u003e2025–2026\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eKawasaki\u003c\/td\u003e\n\u003ctd\u003eKX250X\u003c\/td\u003e\n\u003ctd\u003e2025–2026\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003cp class=\"trd-caption\"\u003eFitment as listed by Yoshimura for part number 242950S521.\u003c\/p\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--accessories\"\u003e\u003ch2 class=\"trd-section-title\"\u003eSound Inserts \u0026amp; Spark Arresters\u003c\/h2\u003e\n\u003cdiv class=\"trd-table-wrap\"\u003e\u003ctable class=\"trd-table\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth scope=\"col\"\u003ePart Number\u003c\/th\u003e\n\u003cth scope=\"col\"\u003eType\u003c\/th\u003e\n\u003cth scope=\"col\"\u003eIncluded With This System\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eINS-31-K\u003c\/td\u003e\n\u003ctd\u003eSound Insert\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eINS-39-K\u003c\/td\u003e\n\u003ctd\u003eSound Insert\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSA-21-K\u003c\/td\u003e\n\u003ctd\u003eSpark Arrester\u003c\/td\u003e\n\u003ctd\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\u003c\/section\u003e\u003csection class=\"trd-section trd-section--docs\"\u003e\u003ch2 class=\"trd-section-title\"\u003eInstallation \u0026amp; Documents\u003c\/h2\u003e\n\u003cp class=\"trd-docs\"\u003e\u003ca class=\"trd-button\" href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0585\/4884\/6743\/files\/yoshimura-242950s521-installation-manual.pdf?v=1792275638\" target=\"_blank\" rel=\"noopener\"\u003eInstructions \/ What's Included (PDF)\u003c\/a\u003e\u003c\/p\u003e\n\u003cp class=\"trd-caption\"\u003eProvided by Yoshimura. Opens in a new tab.\u003c\/p\u003e\u003c\/section\u003e\n\u003c\/div\u003e","brand":"Yoshimura","offers":[{"title":"Default Title","offer_id":68080805609623,"sku":"242950S521","price":999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0585\/4884\/6743\/files\/yoshimura-242950s521-rs12-stainless-exhaust-main.jpg?v=1792275645","url":"https:\/\/allamericanktm.com\/products\/yoshimura-rs-12-stainless-full-exhaust-for-kawasaki-kx250f-x-242950s521","provider":"All American KTM","version":"1.0","type":"link"}