Yoshimura RS-9T Full Stainless System (2018 Honda CRF250R) 

It’s no secret that the all-new 2018 Honda CRF250R is lacking some bottom to mid power when compared to the other competitors in the 250 class. Seeing as how I’ve been logging a lot of hours on the machine as of late, I was designated to be the main test rider for the full RS-9T stainless system. Installing the new full system took me less than 20 minutes and the instructions were very detailed. All of the parts that came inside the box fit perfectly and no swear words were thrown while installing the Yoshimura exhaust.. In my opinion, Yoshimura is one of, if not the highest quality exhaust manufacturer in the industry. In my full time job I work in an R&D department of a welding shop and I can tell you first hand that the quality, fit and finish of a Yoshimura exhaust is impressive.


Now to the part that everyone wants to know... Does the Yoshimura help the little red screamer? The simple answer is yes, but who likes simple answers? Not us! With the stock system, the Honda pulled nicely from mid-range to the super high rev limiter, but when exiting corners and trying to grunt up obstacles, the engine needed some help. The best way to explain the stock feeling CRF250R is that it’s similar to a 125 two-stroke. By saying that I don’t mean it’s as slow as one, but I felt like I had to shift my riding style from four-stroke to two-stroke mode. I had to ride a gear lower at times in corners (than other 250F machines), and if I didn’t, it took a bit of clutch feathering and more shifting to get the bike pulling hard again.


As soon as I fired the bike up with the new exhaust it was clearly a bit louder, not obnoxious, but a nice, throaty sound that was deeper and less raspy. I tested the stock system back to back with the Yoshimura system on the same days, so it was cool to see the places on each track where the bike really felt different. The most noticeable place the bike felt better was out of tight inside ruts that exited up faces of jumps. With the stock system I had to slightly slip the clutch all the way up the lip (to be able to clear the jump). When I bolted on the Yoshimura system I could leave it in that same gear and just use the meat of the new found power to pull me up and over those types of jumps. Where I had to be in second gear and then scream the bike on the exit with the stock system, I could now be a gear higher and use the smoother/stronger part of the power to exit the turn with the Yoshimura mufflers. From mid to top I didn’t notice any real added power gains, but I also didn’t feel like the top end suffered in order to fix the bottom end. I’m by no means saying that bolting on an aftermarket exhaust will make your Honda feel like it has a Yamaha 2018 YZ 250F bottom end delivery, but it definitely helps close the gap and make the bike more enjoyable and easier to ride. If you have a 2018 Honda CRF250R and feel like you’d like a bit more bottom-mid range power I’d definitely look into the RS-9T system. There are three options Yoshimura offers, the slip on mufflers ($789.00), the full stainless system ($977.00), and the full titanium system ($1499.00). Admittedly none of these are super cheap options, but it is one of the few things in today’s four-stroke world that provides a true bolt on benefit. Besides, if you were cheap you’d still be riding your old clapped out POS instead of your sweet 2018 Honda. -Michael Allen 


I concur with Michael Allen on these findings. Michael is a great off-road rider and is an improving novice type of motocross guy. In order to please a wide range of abilities and riders when making an exhaust is not and easy task. I feel like Yoshimura has done that with their 2018 CRF250R exhaust system. I get more rpm response down low and it adds some excitement to the crack of the throttle. I love the chassis of the new generation Honda CRF250R, but it is hurting for some bottom end, in stock trim. The Yoshimura helps wake up some of that bottom-mid range and instead of getting a hollow/empty feeling down low (especially when the dirt is tilled deep), now I have some more “meat” to work with coming out of corners. I still can’t run third gear in corners, but I most certainly can shift earlier coming out of them. I also agree with Michael that the Yoshimura muffler didn't lose any up top when compared to the stock system. If anything I feel like it was a little stronger than the stocker, which is impressive. I also think the stainless system is just as cool as stock (because I am saving money), but you will only be losing a little over half a pound instead of over three pounds with the titanium version. -Kris Keefer