Yoshimura RS-4 Slip-On Exhaust KTM 790/890 Adventure

I wanted a slip on muffler that gave an audible exhaust note. the stock unit was so quiet, all I could hear was the strange noises of the LC8 890 engine. I definitely did not want the excessive noise achieved with a cat delete. The RS-4 gives a nice deep tone way better than stock without the obnoxious noise levels of decat. It is exactly what I wanted, a low, sporty tone without being too much. The power seems to be better than stock. From idle on up, seems to pull smoother and easier. Cruising I'm often able to putt along in one gear higher than when stock. The fit and finish are beautiful. Much better price point than other slip ons. Overall very happy with the product and my purchase!

Was wanting an aftermarket exhaust to set my 2021 KTM Adventure R apart from the other adventure bikes that my friends ride. Came across the Yoshimura RS-4 slip-on and decided to give it a try based on the claimed horsepower and torque gains in the description details of 5.5% in max HP and 4.7% in max torque. After a very simple removal of the stock exhaust and a simple installation of the RS-4 exhaust it was time to take it for a ride and see if the claims were true. The first thing I noticed was that the 890 was wanting to stall while idling so I figured it just needed to warm it up. After warming it up for five minutes it still wanted to stall. I decided to take it for an extended ride to see if that might resolve the stalling issue. Right away I noticed a better sound from the Yoshimura exhaust versus the stock KTM exhaust. It is a much lower rumbling sound from the RS-4 can versus the pinging sound of the stock can. As I twisted the throttle it sounded better as the RPMs increased. As the sound got better so did the performance in the mid to higher RPM range in the blacktop. Off road and in the dirt the performance also felt better in the soft packed dirt and when climbing hills. Before the exhaust upgrade I would have to keep the throttle more open for the deeper mud and steeper hill climbs but after the upgrade the 890 seems to accomplish those obstacles easily in the midrange and more impressively at the higher RPM range. Also, the look of the carbon fiber end cap and heat shield combined with the metal heel protector looks much better than the stick exhaust in my opinion. I did notice that the length of the Yoshimura is longer than the stock exhaust by about 1” to 1 1/2” but even that compliments the overall improvement in the look of the exhaust. I do however with that Yoshimura would more closely match the stock exhaust connection of the can bracket to the bike frame rail bracket as I do like the stock one better with the torx bolt, sleeve and rubber isolator mount. I highly recommend this Yoshimura RS-4 slip on both for better performance and for improved bike aesthetics.