Yoshimura · RS-4 · Full System
The Yoshimura RS-4 Race Series Exhaust System is a full system designed for Honda CRF450L-International 2019–2025 and Honda CRF450X-International 2019. Built around a stainless system with an aluminum muffler, it’s aimed at riders who want a more capable exhaust setup for dual sport and off-road use.
This International Model application is identified as not for use or sale in USA. Yoshimura developed this system to improve power delivery and make the bike easier to ride across a range of off-road conditions, while also reducing weight for a balanced overall package. See the fitment table below to confirm the exact model listing.
This Race Series RS-4 setup is a complete full exhaust system for the international CRF450L/X platform. It’s designed as an integrated package, pairing the system layout with Yoshimura’s RS-4 series design approach for dual sport and off-road riding needs.
The header pipe uses a tucked-in routing intended to help keep it less exposed to damage in off-road conditions. Yoshimura also specifies a thicker 18 gauge header construction to provide better impact-protection where trail hazards and debris are common.
A lambda/O2 sensor bung is included in the system design, supporting installations that require an oxygen sensor location. This detail helps streamline fitment on the specified international CRF450L and CRF450X applications.
Fitment
This exhaust is specifically listed for Honda CRF450L-International 2019–2025 and Honda CRF450X-International 2019. It is identified as an International Model application and is stated as not for use or sale in USA. For exact model coverage, reference the fitment table on the page.
Performance
Yoshimura developed the RS-4 system after getting access to the international CRF450L, focusing on improving power delivery while keeping the machine easier to manage in varied off-road conditions. Key design details include a tucked-in header layout intended to reduce exposure to impacts, along with a thicker 18 gauge header spec aimed at better impact-protection.
Materials
This Yoshimura Race Series Exhaust System is an RS-4 full system with stainless listed as the material in the specifications table, and the product name calls out an aluminum muffler. Additional listed details include a shipping weight of 14 lb and barcode 00840025909717. The page also provides an installation PDF for reference during setup.
| Part Number | 124500D320 |
|---|---|
| Brand | Yoshimura |
| Product Line | Race Series Exhaust System |
| Series | RS-4 |
| System Type | Full System |
| Material | Stainless |
| Shipping Weight | 14 lb |
| Barcode | 00840025909717 |
| Emissions Compliance | QUALIFIED MANUFACTURER DECLARED "MODIFIED PART" |
| Make | Model | Model Years |
|---|---|---|
| Honda | CRF450L-International | 2019–2025 |
| Honda | CRF450X-International | 2019 |
Fitment as listed by Yoshimura for part number 124500D320.
Instructions / What's Included (PDF)
Provided by Yoshimura. Opens in a new tab.
