MXA TEAM TESTED: YOSHIMURA RS-4 PRO SERIES RM-Z250 EXHAUST

WHAT IS IT? Composed of titanium and carbon fiber and developed for Team Suzuki’s 250 program, the Yoshimura RS-4 Pro Series RM-Z250 exhaust system is the cream of Yoshimura’s crop.

WHAT STANDS OUT? Here’s a list of things that stand out with the Yoshimura RS-4 Pro Series RM-Z250 exhaust.

(1) Problem. The 2011 Suzuki RM-Z250 is blessed with the best engine in the class. It isn’t the most powerful or durable, but it has a racer’s powerband that begs to be ridden hard and doesn’t falter; however, the RM-Z250 engine isn’t perfect. The RM-Z250 is only so-so in the top end and lacks significant over-rev. The MXA wrecking crew was looking for, as Tim “The Toolman” Taylor would say, “More power!”

(2) Performance. It was immediately apparent that the Yoshimura RS-4 is a pro-level exhaust. The Yoshimura RS-4 system boosted midrange to top-end power without affecting bottom-end power. Advanced and pro-level riders raved about the RS-4’s ability to change the RM-Z250’s engine characteristics by essentially waking up the bike. Riders raved about the lighter-feeling throttle response and vastly-improved over-rev. To summarize, the Yoshimura RS-4 Pro Series RM-Z250 exhaust system did exactly what we had hoped.       

(3) Installation. Yoshimura provides the proper hardware, including a rubber grommet and aluminum spacer for the muffler. After switching between the RS-4 exhaust and the stocker several times, we noticed that the area between the mid-pipe and muffler on the Yoshimura system twisted. This didn’t create a performance issue, but made installation difficult. Pay close attention when attaching the mid-pipe/muffler section to the head pipe?and always anti-seize the slip-fits.

(4) Price. Yoshimura understands that not every consumer is interested in their lightest possible, and thus most expensive, exhaust system ($995), so they are offering three options: The $595 Comp Series exhaust is a stainless steel pipe with an aluminum muffler and has the same dimensions as its more expensive brethren. Additionally, there is a slip-on, with a stainless steel mid-pipe, aluminum muffler and carbon fiber end cap.

(5) Place of manufacture. The RS-4 exhaust system is made in Chino, California.

WHAT’S THE SQUAWK? We have two complaints.
 
(1) Price. Your wife won’t believe that a $1000 exhaust system is more important than the mortgage.

(2) Installation. Be sure not to twist the mid-pipe/muffler section onto the head pipe.

The Yoshimura RS-4 Suzuki RM-Z250 exhaust pipe improves mid-to top-end power and over-rev, weighs quite a bit less than stock and has a factory finish. Bravo!