Yoshimura Signature RS-9T Titanium/Carbon System

Price: $1499.00

When we first broke the news with images of the prototype 2018 Honda CRF250R last October when it was raced in the All Japan National MX Championship Series by Honda’s Takeshi Katsuya, the majority of the comments from skeptics were about the bike’s dual-exhaust design. Taking Honda’s dual-muffler design one step further, the ’18 CRF250R comes with two complete exhaust pipes – one on each side of the bike – to take advantage of the power gains that a truly straight intake and exhaust path can yield. “Two pipes will cost twice as much!” complained some. True, with the greater quantity of materials needed to produce a true twin-pipe system mandates a higher end price tag, the Yoshimura Signature RS-9T Titanium/Carbon Fiber system for the 2018 bike costs only about $100 more than the twin-muffler system from ’17, and $500 more than a single-sided system for say, a Suzuki RM-Z250.

The Yoshimura Signature Series RS-9T Titanium/Carbon Fiber system for the 2018 Honda CRF250R is the brand’s flagship system for the exciting new bike, and production units just started to roll off the assembly line. Stainless steel and aluminum versions with identical performance gains have been available for over a month and cost $977, but Yoshimura wanted us to wait to test the top-of-the-line system.

We took delivery of a system earlier this week and have spent a couple days riding our test bike since. The first thing we must make note of is the packaging that the system comes in. In the past, Yoshimura exhaust systems have come in a box either filled with styrofoam peanuts, or “sealed inside” a spray-in foam packing material that often reminded us of the way Han Solo was cryogenically frozen and transported to Jabba the Hutt. The newest system was protected inside folded cardboard wraparound panels, with the air space in the box filled with a one-piece shredded cardboard padding material. This observation doesn’t affect the way the pipe performs, of course, but we didn’t find ourselves chasing styrofoam pieces across the pits or catching disapproving stares from our wives when the packing got all over the living room carpet…

The system (s) are beautiful works of art. But then again, everything that Yoshimura produces has a refined, finished look. Because of the twin-pipe design, the headers seem almost as small as the systems we would bolt on our CRF50s in the days when pit bikes were all the rage. In spite of the fact that you have to remove and install two separate exhaust systems, the process is very simple and takes only about 20 minutes to install both sides completely. The RS-9T system bolts on with precision and everything fit perfectly. Granted, out test bike has not been crashed and bent up (yet), but everything fit so perfectly that there was absolutely no jiggling or prying involved in the installation. The header pipes are tucked away quite well from the rider’s boots, and the mufflers are short and tucked away from harm’s way.

As usual, we began to install the system without reading the directions. (We’re men: what do you expect?) When it came time to install the springs on the header pipe, we noticed a small bracket in the packaging. After reading the directions (novel idea!), we discovered that it was to relocate the electric starter wire out of harm’s way from the left-side header pipe, which is either tucked in closer than stock, of a larger diameter, or both. Whatever the case, installing the bracket and re-inserting the wire clip was a cinch and it is awesome that Yoshimura would pay such attention to detail and include such a part.

When installing the mufflers, one must take care not to mix up the mid-pipe and muffler mount bolts, and doing so will cause the longer mud-pipe bolt to bottom out against the subframe if used in the muffler bracket. This will lead to a loose fit and could result in some vibration damage. (Yes, we put the two bolts in the wrong places and figured out our mistake before riding…) Our only complaint about the construction of the system is the flange and spring systems used to attach the headers to the cylinder. But, while a simple bolt-on flange may be simpler and quicker to install, using springs to firmly hold the headers in place allows for some give, better resists cracking of the header from vibration, and lastly, serves as a second system of attachment to guard against mid-race DNFs.

All told, the system weighs 3.3 pounds less than the stock pipes, a significant weight savings that certainly has a positive effect on the bike’s center of gravity and handling character. When we first fired up our test bike with the RS-9T installed, we were surprised to hear its mellow exhaust note. While idling and even revving up the bike on the stand, the system doesn’t sound any louder than stock…it only has a slightly higher pitched bark when you crack the throttle. Yoshimura claims that in sound testing the mufflers – which have greater packing volume than the stockers – actually test at a lower db than stock. On the track, the system does sound louder than stock, but not obnoxiously so.

At the crack of the throttle, low-end performance is improved quite a bit. Stock, the CRF250R lacks low-end but really begins to shine from the mid-range on up, with massive pulling power in each gear on top. With the Yosh system installed, the CRF250R takes on a more aggressive, peppier personality. From the second you crack the throttle, rpms build more quickly and the bike has a bigger hit down low that is great for bursting out of tight, inside lines. So aggressive is the bike down low with the system installed, that it was at first tougher to roll through slippery flat corners at low throttle positions because the bike is so responsive. A few laps of acclimating to the snappier powerband, however, and this problem was a thing of the past.

As the rpm begin to build, the Honda still enjoys a super-strong mid- to top-end power delivery with the same far-revving character, only boosted a couple horsepower throughout. It should be noted, however, that because the system coaxes more torque out of the CRF, that the bike rips through each gear quicker and this could give the illusion of less overrev in each gear. Not the case!

Jason Fischera puts our Yoshimura-equipped 2018 CRF250R through its paces at Milestone MX.

The Verdict

The Yoshimura Signature RS-9T Titanium/Carbon Fiber exhaust system for the 2018 Honda CRF250R adds a very noticeable amount of performance and power to the bike, addressing it’s only flaw: a lack of low-end power. Beautifully built, lighter in weight, quieter and better performing, the twin pipes from the crew at Yoshimura are worth their weight in gold. Or is that titanium?