Yoshimura RS-4 Race Series Non-CARB Compliant Complete Exhaust System

The Yoshimura RS-4 Race Series Complete Exhaust System is the result of the same championship-winning R&D used to power riders like Ryan Dungey to AMA Supercross and Motocross titles. Engineered for maximum performance with a refined exhaust note, the RS-4 delivers a distinctive combination of increased power, reduced noise, and race-focused durability. This system features Yoshimura’s advanced polyresonant duplex chamber, stepped baffle design, and a signature carbon fiber end cap—making it one of the most technically innovative exhausts in the sport.

Key Features

Stainless Steel Construction

• Stainless steel header and tail pipe provide long-lasting strength and heat resistance.
• Designed to withstand demanding race-level riding conditions.
• Pentagonal Muffler With Integrated Noise Management
• Pentagonal sleeve enhances internal volume and exhaust flow.
• Front muffler cap functions as a polyresonant chamber, reducing exhaust noise without restricting power.
• Laser-cut heat shield protects the rider and gives a premium aesthetic.

Advanced Performance Engineering

• Two-stage stepped baffle improves exhaust scavenging for stronger mid-range and top-end power.
• Carbon fiber turn-out end cap provides lightweight durability and a race-bred appearance.
• Designed using R&D from championship-winning teams.

Race-Series Design

• Built exclusively for closed-course competition where maximum horsepower and throttle response are essential.

Benefits

• Increased horsepower and torque, especially in the mid and upper RPM range.
• Reduced weight compared to stock systems, improving handling and acceleration.
• Quieter performance for a race exhaust, thanks to Yoshimura’s polyresonant chamber technology.
• Premium materials and craftsmanship, extending product longevity.
• Race-proven performance backed by Yoshimura’s legacy in AMA racing.

Ideal For

• Motocross and off-road racers
• Riders seeking improved throttle response and top-end pull
• Performance-focused builds

Technical Details

• Header / Mid-Pipe: Stainless steel
• Muffler: Pentagonal design with polyresonant chamber
• End Cap: Turn-out carbon fiber
• Baffle: Two-stage stepped design
• Use: Closed-course competition only
• Compliance: Not CARB compliant; not legal for use on California public highways

Legal & Compliance Notice

• This system is NOT CARB compliant and is not legal for sale or use on any pollution-controlled motorcycle in California unless used strictly in closed-course competition. Check local and federal regulations before installation.