Yoshimura R&D of America, Inc.

WR450F 12-15 RS-4 Stainless Full Exhaust, w/ Aluminum Muffler

WR450F 12-15 RS-4 Stainless Full Exhaust, w/ Aluminum Muffler - Main image
$507.54 $769 In stock

Category: Enduro Series Exhaust System

The RS-4 offers a unique design that provides an unrivaled combination of power and a quiet exhaust note.

The work that went into developing the RS-4 muffler has paid big dividends in Off-road Racing; winning multiple Supercross and Motocross titles since it's inception. We've developed the current generation RS-4 based on that research & development, and the result is a unique design that provides an unrivaled combination of power and quiet exhaust tone. The RS-4 features a Polyresonant duplex chamber and two-staged stepped baffle for increased performance, while a carbon cone end cap finishes off its innovative styling.

  • Pentagonal-shaped sleeve
  • Front muffler cap functions as a polyresonant chamber which helps reduce noise
  • Two-stage stepped baffle
  • Turn-out carbon fiber end-cap
  • Stainless steel header and tail-pipe
  • Repack Kits, optional Inserts and Spark Arresters are available for all models
Before you pay

Check the method and total at checkout.

When it ships

Allow for processing time as well as the journey to you.

Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

View policy
If you need a refund

Keep your order number and contact the store to start.

Please contact us for the refund processing timeframe before returning an item.

View policy
Delivery costs

Review the cost for your destination and chosen service.

Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

View policy
Returning an item

Check the return conditions before sending anything back.

United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

View policy

Customer Reviews (4.6 / 5 · 5 reviews)

Matthew ★★★★★

I was impressed by how much smoother the power delivery feels with this system, and the stainless steel construction seems built to last through rough rides. The sound is noticeably quieter than my old pipe, which is a huge plus for keeping the neighbors happy on early morning trail runs.

Daniel A. ★★★★★

I was surprised how much low-end grunt this added without making the bike obnoxiously loud. The aluminum muffler shaved off noticeable weight compared to the stock unit.

Ava I. ★★★★★

The RS-4 full system bolts right onto my 2014 WR450F and the stainless header looks like it belongs in a factory race garage. Even with the aluminum muffler, the exhaust note stays surprisingly mellow for how much extra snap it gives in the mid-range. Rode a whole desert loop and my ears weren't rin