Yoshimura · RS-4
The Yoshimura Sound Insert Kit RS-4 Muffler, 1.500" ring (INS-22-K) is a replacement low-volume insert kit designed for Yoshimura RS-4 mufflers. It’s built to provide an optional sound-restriction setup when an application calls for different sound limits, with results that vary by application.
This kit is listed for Honda CRF450X 2019–2026. Fitment details are application-specific, so the fitment table on the page should be used to confirm compatibility before installation.
Designed as a replacement low-volume insert kit for RS-4 mufflers, this setup provides an option for applications that require different sound restrictions. Yoshimura notes that decibel reduction depends on the specific application, so outcomes can vary by model and configuration.
This insert kit is identified as non-spark arrested. It is intended for riders who specifically need a low-volume insert configuration, but spark-arresting functionality is not part of this kit as listed.
The kit includes the key components needed for installation: a low-volume insert tube, an end-cap collar, and a set screw. An installation PDF is provided on the page to support correct assembly and fitment verification.
Sound
Yoshimura lists INS-22-K as a replacement low-volume insert kit for RS-4 mufflers, offering an optional approach for applications requiring different sound restrictions. Because sound output can vary across setups, Yoshimura specifies that decibel reduction depends on the application. For riders maintaining an RS-4 system, this service-part kit supports a consistent, component-correct solution.
Fitment
This Yoshimura RS-4 sound insert kit is listed for Honda CRF450X 2019–2026. Since fitment and sound behavior can be application-specific, the page fitment information should be reviewed prior to purchase and installation. Yoshimura also recommends confirming compatibility using the insert chart referenced on the product page details.
Installation
INS-22-K is supplied with the parts called out by Yoshimura for the insert assembly: a low-volume insert tube, an end-cap collar, and a set screw. For guidance during installation, the page includes an installation PDF to reference during setup and assembly steps.
| Part Number | INS-22-K |
|---|---|
| Brand | Yoshimura |
| Product Line | Replacement Service Parts |
| Series | RS-4 |
| Shipping Weight | 1 lb |
| Barcode | 00840025908789 |
| Make | Model | Model Years |
|---|---|---|
| Honda | CRF450X | 2019–2026 |
Fitment as listed by Yoshimura for part number INS-22-K.
Instructions / What's Included (PDF)
Provided by Yoshimura. Opens in a new tab.
