Product image 1KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler
Product image 2KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler
Product image 3KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler
Product image 4KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler
Product image 5KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler
Product image 6KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler
Product image 7KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler

*Product may vary by application

KX250/X 21-24 RS-12 Stainless Full Exhaust, w/ Aluminum Muffler

SKU: 242940S320

Sound Insert/Spark Arrester Options

Regular price $879.00


Signature Series Exhaust System


over $100


Repair Services

Same day shipping on In Stock items placed Mon-Fri by 1:00 pm PST. Please contact sales@yoshimura-rd.com for ETA's on Reserve Now / Pre-Order Items.


WARNING: Cancer and Reproductive harm - www.p65warnings.ca.gov

In a word, POWER! That's what our new RS-12 Signature Series full systems delivers for the all new Kawasaki KX250 Motocross machine.

Our new RS-12 adds lots of power to the new and improved 249cc Kawasaki powerplant. The goal was to add more usable power and torque to almost the entire power curve. Boasting an increase of max HP of 4.5% (at 12,000 rpm) and a max torque increase of 7.7% (at 6,700 rpm) RS-12 lays the power down to where it needs to be!

Of course the RS-12 has more features than just power. Its machined joints, PTF sound inserts, asymmetrical shape are all performance enhancing. With a matte carbon fiber end cap and that Yoshimura bark will make your KX250 the most distinctive on the track!

Yoshimura RS-12 and the Kawasaki KX250 are ready for the podium!

Kawasaki KX250 RS-12 Features and benefits:

  • Aggressive intelligently designed, the RS-12 asymmetrical shaped muffler allows maximize capacity and incorporates a resonance chamber for managing sound and increasing usable power. RS-12's unique profile also provides more clearance for tire and brake caliper.
  • Tapered muffler body inlet design of RS-12 enables the system to be pushed forward in the new Kawasaki chassis thus helping with weight centralization without sacrificing performance.
  • Improved performance gains with refined linear power delivery.
  • Just like the works systems our Factory Racers use, RS-12 systems utilize precision machined joints. Machined joints provide a superior and exacting fit for joints by better securing the seal between two surfaces with a perfect 360 degree contact surface which translates into improved system life, fit and performance.
  • New patent pending Precision Taper Fit (PTF) insert ring makes it easy to install and remove sound inserts and spark arresters.
  • Works-look matte carbon fiber end cap with industry leading design, innovation and detailing as expected from Yoshimura.
  • Carbon end cap covers the RS-12 inner cap, thus improving looks, while providing easier service as compared to other sandwich mounting designs most commonly found in the industry.
  • Proudly designed, developed and made in the USA!
  • Repack Kits, optional Inserts and Spark Arresters are available for all models

Sound Insert/Spark Arrester Options                 
Sound Level
Volume Insert Spark Arrestor Included

SA-21-K No 


. . . . .

This product was designed to fit on a standard equipped motorcycle, as delivered from the factory. OE and aftermarket accessories not found on a bike as delivered from the factory may not be compatible with this product.

Attention international customers: This product was designed and tested to be compatible with vehicles in the U.S. marketplace only. Compatibility, including fitment and performance, may vary by marketplace.

Signature Series Exhaust System

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Introducing Signature Series by Yoshimura - an offering of exhaust systems that a dealer can install with confidence. Our Signature Series lineup is the answer for today's dealer who is faced with a challenging marketplace. The applications for the Signature Series line cover the entire powersports spectrum, including many of our off-road applications. Every one of our Championship Winning Motocross exhaust systems and nearly all of our ATV/Side-by-Side applications are members of the Signature Series Family. All Signature Series components are tested, documented, and marked as required by federal and state regulations.

Vehicle Fitment

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  • Kawasaki KX250F 2022
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  • Kawasaki KX250F 2024
  • Kawasaki KX250X 2021
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    Race series product restriction and affirmation


    The RACE SERIES product you are purchasing removes, renders inoperative, or bypasses required elements of the emission control systems of EPA, certified motorcycles of motorcyle engines and may only be installed on motorcycles that are restricted to closed course competition. Installation of this product on a motorcyle that is ridden on a public street, highway, or public lands violates the tampering and defeat device provisions of the Clean Air Act & 203(a)(3)(A) and/or & 203(a)(3)(B) and may subject you to a civil penalty of up to $37,000.

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    By clicking below, I affirm:
    1. that i have read the above warning;
    2. that any information I have entered is accurate; and
    3. that any motorcycle on which I install the RACE SERIES product will be restricted to closed course competition and will not be ridden on any public street, highway or public lands.