SKU: 17605036900

Yoshimura - RS-4 Full System (Kawasaki)

Sale price$355.05 Regular price$394.50
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Ships within 48 hours · Estimated delivery Sep 11 - Sep 16

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Description

Yoshimura - RS-4 Full System (Kawasaki)Yoshimura RS 4 Signature Series Full System (Kawasaki) The Yoshimura RS 4 Signature series full exhaust system for Kawasaki has been developed to win races. Adding power throughout the range and providing torque to help the KX250F get out of the gate to grab holeshots, the RS 4 system gives the rider confidence to battle with the best. The RS 4 has also been designed to save weight and add monster performance over the stock system. The unique

Yoshimura - RS-4 Signature Series Full System (Kawasaki)

The Yoshimura RS-4 Signature series full exhaust system for Kawasaki has been developed to win races. Adding power throughout the range and providing torque to help the KX250F get out of the gate to grab holeshots, the RS-4 system gives the rider confidence to battle with the best. The RS-4 has also been designed to save weight and add monster performance over the stock system. The unique Pentagonal-shape sleeve gives your bike that factory look while adding an exhaust note that isn’t loud thanks to the Polyresonant duplex chamber and two staged stepped baffle for increased performance. Adding to the factory look, the RS-4 includes a Stainless Steel header pipe that is durable and is finished off with a Carbon Fiber cone end cap.

For riders looking to shave off even more weight, the RS-4 Signature series for Kawasaki comes in two Titanium versions to match anyone’s factory look. Yoshimura has done it again and offered factory equipment for any rider looking to increase power on their motocross bike.

With years of involvement in professional racing, Yoshimura did not hold back in the development of the RS-4 Signature Series for Kawasaki motocross bikes. From their clean look to their fit and finish, Yoshimura exhaust systems are the built to the highest standards so you don’t have to worry about loss of power at the wrong time.

You can find all your Yoshimura RS-4 Signature Series Full Exhaust systems for Kawasaki at BTO Sports, where we have the best prices and availability for your bike. While this particular offering from Yoshimura is for the 2017 Kawasaki motocross bikes such as the KXF250, we also carry parts for KTM, Yamaha, Honda, Suzuki, and Husqvarna as well. Be sure to check BTO often for the latest dirt bike parts like the Yoshimura RS-4 Signature Series Kawasaki Full System.

 

Features:

  • Pentagonal-shaped sleeve
  • Front muffler cap functions as a polyresonant chamber which helps reduce noise
  • Two-stage stepped baffle
  • Carbon fiber end-cap
  • Offered in three models:
  •  - Stainless header, Aluminum can w/ Carbon End Cap
  •  - Titanium header, Titanium can w/ Carbon End Cap
  •  - Titanium header, Carbon can w/ Carbon End Cap

 

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 17605036900

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4.5 ★★★★★
Based on 11 reviews
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Diane
Lake Worth, US
★★★★★ 5
Great!
Size: Small, Color: Black/Heather Gray/White/Nude
Comfy, good fit, good quality cotton and flat seams around the crotch. Normal size small. I wouldn’t wear these with yoga pants, but nice under looser fitting garments. I would buy more colors.
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Reviewed in the United States on May 28, 2026
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Verified Purchase
Arsenio Braga
Draper, US
★★★★★ 5
There is a seam up the front. I think perhaps it being seamless would be better.
Size: Medium, Color: Black
Like anything off Amazon I wasnt expecting anything perfect and ready to have to mail it back. Pleasantly surprised by the softness and durability. The waist band isn't to small on a medium so it fits actually so comfy. I wear them as underwear and as shorts for my skirts n dresses. Id recommend but I say size up if you want a comfy fit. But down if you want a fitted fit fit. Comfy still is fitted but better feeling on if that makes sense. Also the crotch of the shorts/undies has essentially extra fabric sewed in creating that nice comfort. Ill snag a photo when I have time.
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Reviewed in the United States on May 3, 2026
S
Verified Purchase
Stephanie Vaughn
Waukegan, US
★★★★★ 4
Product varies from package to package
Size: X-Large, Color: Black/Navy/Dark Purple/Red
Over a two year period this is my 4th purchase. They started as sleep shorts and have replaced other underwear most of the time because they are comfortable and the quality is pretty good. However there are differences in between every package. The length has varied up to an inch, the material has changed, and some are slightly tighter than others. That said it works for me. I am a side sleeper and sometimes the side seam bothers me.
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Reviewed in the United States on March 9, 2026
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Verified Purchase
House of Squawk
Battle Creek, US
★★★★★ 5
Very comfortable in the Texas heat.
Size: Small, Color: Black/Navy/Dark Purple/Red
I got some of these as a gift and I loved them so much I purchased two more packs. I just opened my new packs and put them in the washer so I'm not leaving a photo. When I wear them they look exactly like they do on the models. I've been doing a lot of heavy outdoor work in the heat and I get drenched. These underwear have a 100% cotton crotch and the rest is 95% cotton and 5% spandex. When I first saw the wide crotch I didn't think I would like it. But these are soooo comfortable. I'm 4'11" and weight 108-112 and the size small fits loosly but well. I could probably get away with an XS but I like this loose and not too tight fit. I see some folks say these roll up. They don't roll up on me. I think they might roll if they were tight fitting. I have lots of other undergarments like these and some roll and some don't. But none of the others are cotton. They are mostly spandex and since I've found these in cotton that's all I'm wearing until summer is over. I can't feel them or see them under pants or skirts. These look more like shorts than underwear and they have a very nice thickness. Since I only had four pair to begin with, those got washed and dryed a lot. I can't tell if they shrunk since I only tried them after washing. Sorry I forgot to compare the size of the new ones to the older ones before I threw them in the washer. I'll probably buy another set and compare at that time. One thing I can report is that they do not fade at all. I just washed the black, purple and red colors with the white color and the white is still completely white. Now I have more colors and I'll probably be walking around in my underwear and no one will know. The only con I can think of is the wide crotch wouldn't work well with pads with wings, in my opinion. Try a size larger for a nice cool pair of sleeping shorts to see how they fit while they are on sale. Then go smaller if needed. I think you might enjoy these.
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Reviewed in the United States on July 10, 2024
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Verified Purchase
Shannon
Cuba, US
★★★★★ 5
So comfortable and worth the buy
Size: Large, Color: Black
So comfortable!!! There is no seam in the butt and under neath, only in the front but it is really soft and non irritating. I got these for post partum but I’m already wearing them at 8.5 months pregnant. They’re probably my favorite undies right now. The length is also perfect and the material is very soft and stretchy. The waist band is the same, soft and stretchy.
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Reviewed in the United States on April 11, 2026

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