Yoshimura - RS-4 Full System (Yamaha)

Yoshimura – RS-4 Signature Series Full System (Yamaha)

Developed through years of pro-level racing, the Yoshimura RS-4 Signature Series Full System was built to make Yamaha motocross bikes faster, lighter, and smoother from the gate drop to the checkered flag. Engineered for riders who demand top-tier performance, the RS-4 delivers real power gains across the entire rpm range, with a stronger pull out of corners and a crisp, race-tuned sound that stands out without being too loud.

The RS-4’s pentagonal-shaped muffler is more than just a visual statement — it increases internal volume for improved exhaust flow and tone control. Inside, the Polyresonant Duplex Chamber and two-stage stepped baffle reduce noise while maintaining power, giving your bike that clean factory bark. Each system comes with a stainless steel or titanium header for durability and flow, while the carbon fiber end cap adds a finishing touch worthy of any pro-level setup.

Why We Like It:
It’s the perfect mix of power, precision, and sound. The RS-4 gives Yamaha’s four-strokes that deep, controlled Yoshimura tone and a noticeable boost in torque and top-end pull. It feels like a full factory system — because it is.

Why It’ll Work for You:
This system makes your Yamaha smoother off the bottom, stronger through the mid, and more responsive on top. You’ll get better throttle control, faster acceleration, and less weight — all while keeping noise levels in check. Whether you’re racing or riding hard on the weekends, the RS-4 brings pro-level confidence and reliability.

Variants / Options:
Available in three configurations:

• Stainless Header with Aluminum Canister and Carbon End Cap
  
  

• Titanium Header with Titanium Canister and Carbon End Cap
  
  

• Titanium Header with Carbon Canister and Carbon End Cap
  
  

 

Key Features:

• Developed through years of professional racing
  
  

• Pentagonal muffler design for better flow and unique factory styling
  
  

• Polyresonant Duplex Chamber reduces sound while improving performance
  
  

• Two-stage stepped baffle for smooth power and tone control
  
  

• Carbon fiber end cap for weight savings and durability
  
  

• Improved torque and power across the rpm range
  
  

• Lighter than stock for better handling and acceleration
  
  

• Available in stainless or titanium configurations
  
  

• Handcrafted by Yoshimura in the USA