Yoshimura R&D of America based in Chino, California has been making exhaust and performance parts for over 20 years and Yoshimura Japan since 1954. While Yoshimura Japan’s focus has been on the Asian and Euro markets, Yoshimura R&D of America has been busy supplying championship winning Supercross, Motocross and Sportbike exhaust for the US market.  Most recently they have come out with some new offerings for the Adventure bike. With the 2016 Honda Africa Twin’s popularity and Yoshimura’s long partnership with HRC it was time to get to work.
The New Yoshimura RS-4 Slip-On exhaust is made of durable stainless steel with Works Finish. It is not a coating, but rather a media blast finish that takes on unique coloring that looks much like the titanium works components factory racers use. For our Africa Twin this is a much better look than the polished chrome-like exhaust they previously were using. To save weight they finish it off with Yoshimura’s trademark carbon-fiber end cap, which comes from their in-house composites department. All this makes for a slip-on that is approx. 4 pounds lighter than the stock slip-on, much slimmer and definitely better looking.
Installing the Slip-on was a piece of cake and took about 20 minutes using Yoshimura’s detailed instructions. We’re pretty confident that any amateur garage mechanic can install this with ease. Once you take off the heat shields under the passenger foot pegs, the stock system is removed by one bolt that holds the muffler to the rear subframe and one clamp around the inlet tube. Save all this stock hardware, as you never know when you’ll need it again. Once the stock system was removed the Yoshimura slip-on fit right up to the stock mounting points and heat shields were put back on. Yoshimura recommends wiping the stainless bits down with alcohol so that when the system heats up your handprints are not permanent.


Now it was time to give it a listen. On first start up, there was a definite growl that our twin had not put out before; it was nice! We took our DCT equipped Africa Twin out on the road and what we noticed was a deep growl that was not too loud but lets people know you’re coming. What was clear is that on the Stock equipped DCT bike you really never know where you are in the RPM range because the bike is so smooth and quiet plus the bike shifts automatically. Unless you are someone who loves to stare at an RPM gauge, it’s kind of a mystery. With the Yoshimura exhaust you have a much better sense of RPM’s just by sound.  Like with most slip-ons, once you put a pipe on, it feels like you have more power than stock. In fact, the increase is 6% across the mid-range RPM. 

Out on the road and on high-speed fire roads the sound is awesome. At highway speeds the exhaust drone is at a minimum. This system comes with a low volume insert, which in our opinion is not necessary. But if you are using your twin around the neighborhood, your neighbors may thank you after installation. We installed the insert and you are still able to keep the Yoshimura growl just at lower level dB. One thing the insert did help with was when letting off the throttle the Slip-on did have noticeable pops on de-acceleration without the insert.
If you want your Africa Twin to sound bad ass and have a little more go, we feel the Yoshimura RS-4 Slip-On is a value ad for your riding experience; plus this system is part of their Street Series line. All systems are CARB/EPA tail-pipe emissions compliant, marked with appropriate EPA noise labels. MSRP: $549.00 Click Here for more information.

Chris Glaspell

The success of any online publication depends on the quality of execution, and
in this respect UpShift Online’s success is virtually assured.  It was founded by veteran motorcycle industry professionals: English-born photographer Simon Cudby, the premier photographer in the world of motocross, and Chris Glaspell, creative director with firms serving clients that include Suzuki, Yamaha, Kawasaki, Cycle World and Yoshimura. This, plus Upshift’s veteran editorial staff and unrivaled journalism, will gives readers unparalleled views of adventure motorcycling.