Yoshimura · RS-2 · Full System
The Yoshimura WR125R '26 RS2 Full Exhaust / Aluminum Muffler is a Race Series Exhaust System designed as a Full System for the Yamaha WR125R 2026. Built around Yoshimura’s RS-2 series, it’s aimed at riders who want a more responsive small-bore setup with verified performance gains from the manufacturer.
Yoshimura reports up to 14.7% more hp @7800 rpm and up to 13.3% more torque @7,800 rpm, along with a smoother powerband. This system also includes the SA-02-K spark arrester already installed, and the page provides the supporting dyno chart, product video, and installation PDF for additional detail.
Performance
This exhaust is part of Yoshimura’s RS-2 series within the Race Series Exhaust System lineup. Developed specifically for the WR125R platform as a Full System, it’s intended to help the small-bore engine deliver a smoother powerband while supporting the manufacturer’s verified power and torque claims.
Materials
The system uses an Aluminum muffler, as listed in the specifications. It’s a purpose-built configuration for the Yamaha WR125R 2026, pairing the RS-2 design with materials chosen for a Race Series application while keeping the overall package focused and compact for this model.
Sound
A SA-02-K spark arrester is included and noted as installed with the system. For riders who want to tailor sound output, Yoshimura lists additional sound insert options INS-11-K and INS-12-K as available separately, with included status shown in the sound insert and spark arrester table.
Engineering
Configured as a Full System in Yoshimura’s Race Series Exhaust System product line, this WR125R '26 RS2 setup is designed around the RS-2 platform to target usable performance on the 125cc class. It’s built to bring the system components together as a matched package rather than a single replacement piece, with specifications and system type shown on the page for quick confirmation.
Performance
Performance documentation is provided on the product page, including a dyno chart. Yoshimura reports up to 14.7% more hp @7800 rpm and up to 13.3% more torque @7,800 rpm, and also describes a smoother powerband. For riders comparing options, the verified claims are presented clearly alongside the supporting media shown on the page.
Fitment
Fitment is specific to the Yamaha WR125R 2026, as listed in the fitment table. For installation planning, the page includes an installation PDF and a product video to help confirm what to expect during setup. Spark arrester and sound insert information is also summarized in the dedicated table, including what is included and what is optional.
Figures as reported by Yoshimura.
| Part Number | 131250C350 |
|---|---|
| Brand | Yoshimura |
| Product Line | Race Series Exhaust System |
| Series | RS-2 |
| System Type | Full System |
| Material | Aluminum |
| Spark Arrester | SA-02-K (included) |
| Shipping Weight | 12 lb |
| Barcode | 00840025919969 |
| Emissions Compliance | QUALIFIED MANUFACTURER DECLARED "MODIFIED PART" |
| Make | Model | Model Years |
|---|---|---|
| Yamaha | WR125R | 2026 |
Fitment as listed by Yoshimura for part number 131250C350.
| Part Number | Type | Included With This System |
|---|---|---|
| SA-02-K | Spark Arrester | Yes |
| INS-11-K | Sound Insert | No |
| INS-12-K | Sound Insert | No |
Instructions / What's Included (PDF)
Provided by Yoshimura. Opens in a new tab.
