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Yoshimura RS-4 Comp Series Slip-On Exhaust With Carbon Fiber Header

Retail: $395.99 - $425.99
$359.99 - $395.99
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Product Description

The RS-4 is a unique design with predicated power and a quiet earthy exhaust note that speaks volumes for performance. This RS-4 features all the benefits of the original RS-4 muffler, but with a unique turned-out end-cap, designed to direct exhaust heat and gases away from the bike's components. To top-it-off, they embossed Yoshimura's "347" logo in the carbon for a clean look. With all its benefits in mind, the RS-4 was an obvious choice for the WR450F.

  • Aluminum pentagonal shaped muffler sleeve and aluminum mount bracket.
  • Features a polyresonant duplex chamber, a two-staged stepped baffle, and an innovative carbon cone end cap.
  • Durable high-grade stainless steel tail pipe.
  • Considerable weight reduction.
  • Carbon fiber end cap comes with a 94db U.S.F.S.-approved Spark Arrested insert installed in the muffler.
  • Step-by-step directions and all necessary hardware included for an easy installation.

Note: For closed course competition use only. Not intended for street use.

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1-4 of 5
Ease of Installation
Location: Washington
Great purchase!

I bought this for my 2010 crf250r, immediately noticed that it revs up a lot quicker. Went on with no complications, perfect exhuast system for the mods class. Not to mention the great motosport price! Thanks again motosport for keeping me race ready!

Ease of Installation
Top 1000 Contributor
Location: San Jose, CA
Wake Up Your Bike!!

After buying my 2011 yz450 I began researching what exhaust worked best on the bike. Everywhere I looked they raved about the Yosh and its massive power increase across the board. I decided to order the slip on and find out for myself before I went and bought the full system. Once installed and remapped the EFI the bike pulls longer in every gear, comes out of corners quicker looks great and sounds awesome without being too loud. I am very happy with my choice and recommend this pipe if you want to get those extra ponies.

Yoshimura RS-4 Comp Series Slip-On Exhaust With Carbon Fiber Header
Location: Southern Oregon

Great Buy ,Good Price, Sweet Sound, And a Big pickup on the low end makes the RMZ 250 much more snappy on the low end than stock, We think this was a great investment for the bike and lets us stay in stock classes.

Ease of Installation
Top 250 Contributor
Location: Santa Fe, NM

If you're on a budget and can't afford a full exhaust system, this Yoshi slip on is your best option for the 2010 CRF250R! For the price you really can't beat it. For a slip on it's really impressive! It adds over 1 horsepower, improves the weak bottom end and only adds power to the weak spots. It doesn't trade or take away power anywhere (like some other exhausts). It's also a great looking and premium quality exhaust. has an amazing price on this exhaust too!

1-4 of 5
Total Questions (6)
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1-6 of 6
Matt 1 month 1 day ago
Does this slip on come with a mid pipe and all the parts and do you have to re map the bike?
MotoSport Staff Expert
29 days ago Location: Portland, OR, USA
Yes, this Slip-On would be the Muffler and the Mid-Pipe. Also, normally with a slip-on exhaust you would only need to make minor fuel mapping changes if any at all.
raymond Over 6 months ago
Able to fit on MLE xtm200?
MotoSport Staff
Over 6 months ago Location: Portland, OR, USA
Unfortunately Yoshimura does not offer an exhaust for the MLE brand of motorcycles. In addition, we will not offer any parts specific to this model.
Patty Over 7 months ago Location: Temora NSW 2666, Australia
wanted to no if yushimura has a MX map to suit my 2012 wr450f Im running the RS4-SLIP ON. I have the Yamaha MX map in it at the moment but was just wondering if yushi have one of there own that would make it go a bit harder ??????
MotoSport Staff
Over 6 months ago Location: Portland, OR, USA
Yoshimura will have maps for their ECU hardware but will not offer a map for the Stock ECU. There may be maps available that will accomplish what you are looking for, but will not come directly from Yoshimura. You can even modify the values in the map tables on your own. Take a look at the Yamaha baseline settings for different terrains and you can modify the values to suit your needs. The values can be viewed here :
andrew Over 7 months ago Location: Sydney NSW, Australia
Hi. Can you supply an RS-4 that bolts directly on to a 2013 Triumph 800XC?
MotoSport Staff
Over 7 months ago Location: Portland, OR, USA
Unfortunately we do not carry the RS-4 for the Triumph Tiger 800XC.
Crf104 1 year 1 month ago
Do you have to remap with the slip on or does the cherry bomb already good enough.
MotoSport Staff
1 year 1 month ago Location: Portland, OR, USA
It is necessary to adjust the mapping accordingly in order to have your bike run properly.
carl1 Over 4 years ago
Does the yoshimura RS4 slip on include the spark arrestor?
Over 4 years ago
yes it does go to yoshimura's web site it has all the specs.
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