Yoshimura · RS-4S · Full System
The Yoshimura RS-4S Stainless Full Exhaust is a full system from the Race Series Exhaust System line, built for the Kawasaki Ninja-650 2012–2016 (see fitment table below). Designed around Yoshimura’s RS-4S platform, this system pairs a distinctive pentagonal-shaped sleeve with purposeful internal sound-control engineering.
Yoshimura describes a unique design aimed at delivering a strong blend of power and a quiet exhaust note, featuring a Polyresonant duplex chamber, a two-staged stepped baffle, and an innovative carbon fiber turn-out end-cap. It’s a stainless system with a stainless steel tail-pipe, and it includes the RS4S-INS-1 sound insert.
The RS-4S uses a front muffler cap that functions as a polyresonant chamber to help reduce noise. Yoshimura also calls out a Polyresonant duplex chamber in the system’s design, focusing the exhaust layout on a quieter note while retaining the RS-4S character.
Inside the muffler, Yoshimura incorporates a two-stage stepped baffle as part of the RS-4S design. This internal structure is a key element of how the exhaust shapes sound and response, working together with the chamber design for a controlled exhaust tone.
A turn-out carbon fiber end-cap gives the RS-4S its signature finishing detail and outlet direction. Matched with the pentagonal-shaped sleeve and stainless steel tail-pipe, it completes the Race Series look while keeping the system’s components aligned with the listed stainless construction.
Sound
This RS-4S full system centers on a layout Yoshimura describes as a unique design that balances power with a quiet exhaust note. Key elements include a Polyresonant duplex chamber and a front muffler cap designed to act as a polyresonant chamber to help reduce noise, paired with a two-staged stepped baffle. The result is an RS-4S configuration that prioritizes controlled sound through internal engineering rather than relying on a single component.
Engineering
Yoshimura lists this system as Stainless, with a stainless steel tail-pipe, and finishes it with a turn-out carbon fiber end-cap. The muffler uses a pentagonal-shaped sleeve for a distinctive profile that matches the RS-4S series styling. For riders who want the listed insert included from the start, the specifications note the RS4S-INS-1 sound insert is included, while spark arrester options are presented separately on the page.
Installation
This Yoshimura full exhaust is specified for the Kawasaki Ninja-650 2012–2016. Confirm the exact application in the fitment table below before ordering. For installation planning, the product page includes an installation PDF link, which is helpful for reviewing the system layout and understanding how the full system routes and mounts on the Ninja-650 platform.
| Part Number | 146500D520 |
|---|---|
| Brand | Yoshimura |
| Product Line | Race Series Exhaust System |
| Series | RS-4S |
| System Type | Full System |
| Material | Stainless |
| Sound Insert (Included) | RS4S-INS-1 |
| Spark Arrester | Not included |
| Shipping Weight | 16 lb |
| Barcode | 00840025902978 |
| Emissions Compliance | QUALIFIED MANUFACTURER DECLARED "MODIFIED PART" |
| Make | Model | Model Years |
|---|---|---|
| Kawasaki | Ninja-650 | 2012–2016 |
Fitment as listed by Yoshimura for part number 146500D520.
| Part Number | Type | Included With This System |
|---|---|---|
| SA-13-K-1 | Spark Arrester | No |
| RS4S-INS-1 | Sound Insert | Yes |
| INS-18-K | Sound Insert | No |
Instructions / What's Included (PDF)
Provided by Yoshimura. Opens in a new tab.
