Yoshimura RS-4 Pro Series Full Exhaust System

Item Number: 338937


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Product Description


Yoshimura RS-4 Pro Series Full Exhaust System

The work that went into developing the RS-4 muffler design paid big dividends during development in AMA Pro Racing. That research was directed at developing the RS-4's unique design that provides an unrivaled combination of power and a quiet exhaust note. The RS-4 muffler features a polyresonant duplex chamber, a two-staged stepped baffle and an innovative carbon cone end cap.

  • Pentagonal-shaped sleeve
  • Front muffler cap functions as a polyresonant chamber to reduce noise
  • Two-stage stepped baffle
  • Titanium header and tail-pipe improves flow over the stock exhaust
  • Includes all required hardware and installation instructions
  • Removable low-volume insert

Spec Details
CARB Approved Varies (make selection above)
Country of Origin USA
Header Construction Titanium
Muffler End Cap Carbon Fiber
Muffler Sleeve Varies (make selection above)
USFS Approved Varies (make selection above)

Vehicle Fitment

Fitment is guaranteed or your money back plus free return shipping. Don't waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.


  • CRF250R 2010
  • CRF450R 2009-2012


  • KX250F 2011


  • RM-Z250 2010-2017
  • RMX450Z 2010-2011, 2017

Customer Reviews

Questions & Answers