Yoshimura · RS-4D
The Yoshimura Sound Insert Kit 2M-MAX for RS-4D mufflers is a replacement low-volume insert kit designed for the bottom outlet of an RS-4D end-cap. Built for riders who need a different sound restriction option on specific applications, this kit provides a straightforward way to configure an RS-4D muffler setup as needed.
This non-spark arrested insert kit is listed for Honda CRF450R 2011–2012 fitment. Refer to the fitment table and related insert guidance on the page to confirm the correct application before installation.
Designed specifically for RS-4D mufflers, this insert kit is intended for the bottom outlet of the RS-4D end-cap. It targets the correct end-cap location for the listed application, helping ensure the proper interface when a replacement or optional sound insert is required.
This is a replacement low-volume insert kit for RS-4D mufflers. Yoshimura notes that decibel reduction depends on the application, making this kit a practical option when different sound restrictions are required for a particular setup.
The kit includes the key pieces needed for installation: a low-volume insert tube, an end-cap collar, and a set screw. These components are packaged together as a service replacement to restore or change the insert configuration on compatible RS-4D mufflers.
Sound
Part of Yoshimura’s Replacement Service Parts line, the INS-BF-K Sound Insert Kit is intended as a direct replacement low-volume insert kit for RS-4D mufflers. It is designed for the bottom outlet location on the RS-4D end-cap, supporting riders who need to replace worn components or configure an optional insert to meet application-specific sound restrictions.
Installation
This insert kit is offered as an optional solution on applications that require different sound restrictions. Because the decibel reduction depends on the application, correct selection is important. The page provides the relevant guidance to help confirm proper application before ordering and installing the insert kit.
Fitment
Yoshimura lists this insert kit for Honda CRF450R 2011–2012. Confirm the exact fitment shown on the page before purchase, especially when multiple inserts may be available for similar configurations. An installation PDF is provided on the product page for reference during setup.
| Part Number | INS-BF-K |
|---|---|
| Brand | Yoshimura |
| Product Line | Replacement Service Parts |
| Series | RS-4D |
| Shipping Weight | 0.35 lb |
| Barcode | 00840025917613 |
| Make | Model | Model Years |
|---|---|---|
| Honda | CRF450R | 2011–2012 |
Fitment as listed by Yoshimura for part number INS-BF-K.
Instructions / What's Included (PDF)
Provided by Yoshimura. Opens in a new tab.
