{"product_id":"yoshimura-sound-insert-kit-94db-rs-4s-muffler-1-375-ins-18-k","title":"Yoshimura SOUND INSERT KIT 94db RS-4S Muffler, 1.375\" (INS-18-K)","description":"\u003cdiv class=\"trd trd--yoshimura\"\u003e\n\u003csection class=\"trd-hero\"\u003e\u003cp class=\"trd-eyebrow\"\u003eYoshimura · RS-4\u003c\/p\u003e\n\u003ch2 class=\"trd-headline\"\u003e94db Insert Kit for Yoshimura RS-4S Mufflers\u003c\/h2\u003e\n\u003cp class=\"trd-lead\"\u003eThe Yoshimura SOUND INSERT KIT 94db RS-4S Muffler, 1.375\" (INS-18-K) is a replacement low-volume insert kit designed for RS-4 \"Turn-out End-cap\" mufflers. It’s intended for riders who need an optional insert solution when an application calls for different sound restrictions, with decibel reduction varying by application.\u003c\/p\u003e\n\u003cp class=\"trd-lead\"\u003eThis kit fits Honda CRF250L 2017–2020, Honda CRF250L-Rally 2017–2020, Yamaha WR250R 2008–2020, and Yamaha WR250X 2008–2011. For application-specific confirmation, refer to the insert chart and the fitment table on the page.\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\"\u003eINS-18-K\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-4\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\"\u003eHonda CRF250L \/ CRF250L-Rally; Yamaha WR250R \/ WR250X\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\u003ch3 class=\"trd-card-title\"\u003eRS-4 Turn-out Fit\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eBuilt as a replacement low-volume insert kit specifically for Yoshimura RS-4 \"Turn-out End-cap\" mufflers. It’s a focused service-part solution meant to restore or change insert configuration without replacing the entire muffler assembly.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003ch3 class=\"trd-card-title\"\u003eOptional Sound Control\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eOffered as an optional kit for applications that require different sound restrictions. Yoshimura notes that decibel reduction depends on application, making it a practical choice when adjusting to varying riding areas or requirements.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\u003carticle class=\"trd-card\"\u003e\u003cdiv class=\"trd-card-body\"\u003e\n\u003ch3 class=\"trd-card-title\"\u003eComplete Insert Components\u003c\/h3\u003e\n\u003cp class=\"trd-card-text\"\u003eIncludes the key pieces needed for the insert setup: a low-volume insert tube, an end-cap collar, and a set screw. This combination is designed to provide the correct insert hardware package for the intended RS-4 configuration.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/article\u003e\n\u003c\/div\u003e\n\u003csection class=\"trd-story\"\u003e\u003cfigure class=\"trd-story-media\"\u003e\u003cimg class=\"trd-story-img\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0585\/4884\/6743\/files\/yoshimura-ins-18-k-rs4-main.jpg?v=1792279804\u0026amp;width=1400\" alt='Yoshimura SOUND INSERT KIT 94db RS-4S Muffler, 1.375\" (INS-18-K) – Purpose-Built Service Part' width=\"1400\" height=\"933\" loading=\"lazy\"\u003e\u003c\/figure\u003e\u003cdiv class=\"trd-story-copy\"\u003e\n\u003cp class=\"trd-label\"\u003eSound\u003c\/p\u003e\n\u003ch3 class=\"trd-story-title\"\u003ePurpose-Built Service Part\u003c\/h3\u003e\n\u003cp class=\"trd-story-text\"\u003eAs part of Yoshimura’s Replacement Service Parts line and RS-4 series, the INS-18-K is designed to support RS-4 muffler owners who need a low-volume insert option for the \"Turn-out End-cap\" style. It targets a specific muffler configuration rather than trying to cover multiple designs, helping keep the selection process straightforward when the correct insert is needed.\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\"\u003eIncluded\u003c\/p\u003e\n\u003ch3 class=\"trd-story-title\"\u003eWhat’s Included\u003c\/h3\u003e\n\u003cp class=\"trd-story-text\"\u003eThis insert kit is centered around the low-volume insert tube, paired with an end-cap collar and set screw. Together, these components form the insert assembly needed for the intended RS-4 setup. Installation guidance and product media are provided on the page, including an installation PDF and a product video for added reference.\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\"\u003eFitment\u003c\/p\u003e\n\u003ch3 class=\"trd-story-title\"\u003eFitment Notes\u003c\/h3\u003e\n\u003cp class=\"trd-story-text\"\u003eYoshimura lists fitment for Honda CRF250L 2017–2020, Honda CRF250L-Rally 2017–2020, Yamaha WR250R 2008–2020, and Yamaha WR250X 2008–2011. Because insert fitment can be application-specific, Yoshimura also recommends using the insert chart to confirm the correct match for the muffler and application shown in the fitment table.\u003c\/p\u003e\n\u003c\/div\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\/m8WhKb_gOzI\" title='Yoshimura SOUND INSERT KIT 94db RS-4S Muffler, 1.375\" (INS-18-K) video' loading=\"lazy\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen\u003e\u003c\/iframe\u003e\u003c\/div\u003e\n\u003cdiv class=\"trd-video\"\u003e\u003ciframe src=\"https:\/\/www.youtube.com\/embed\/Tcgfsiqo0fc\" title='Yoshimura SOUND INSERT KIT 94db RS-4S Muffler, 1.375\" (INS-18-K) 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\u003eINS-18-K\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\u003eReplacement Service Parts\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eSeries\u003c\/th\u003e\n\u003ctd\u003eRS-4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eShipping Weight\u003c\/th\u003e\n\u003ctd\u003e0.5 lb\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBarcode\u003c\/th\u003e\n\u003ctd\u003e00840025908758\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\u003eHonda\u003c\/td\u003e\n\u003ctd\u003eCRF250L\u003c\/td\u003e\n\u003ctd\u003e2017–2020\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHonda\u003c\/td\u003e\n\u003ctd\u003eCRF250L-Rally\u003c\/td\u003e\n\u003ctd\u003e2017–2020\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eWR250R\u003c\/td\u003e\n\u003ctd\u003e2008–2020\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eYamaha\u003c\/td\u003e\n\u003ctd\u003eWR250X\u003c\/td\u003e\n\u003ctd\u003e2008–2011\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 INS-18-K.\u003c\/p\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-ins-18-k-installation-manual.pdf?v=1792279800\" 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":68080834216087,"sku":"INS-18-K","price":40.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0585\/4884\/6743\/files\/yoshimura-ins-18-k-rs4-main.jpg?v=1792279804","url":"https:\/\/allamericanktm.com\/products\/yoshimura-sound-insert-kit-94db-rs-4s-muffler-1-375-ins-18-k","provider":"All American KTM","version":"1.0","type":"link"}