Yoshimura R&D of America, Inc.

SOUND INSERT KIT 94db RS-4S Muffler, 1.375" (INS-18-K)

SOUND INSERT KIT 94db RS-4S Muffler, 1.375" (INS-18-K) - Main image
$26.21 $40.95 In stock

Category: Replacement Service Parts

  • Replacement Low-Volume Insert Kit for RS-4 "Turn-out End-cap" Mufflers
  • Non-Spark Arrested
  • Available as optional kit on applications requiring different sound restrictions
  • Decibel reduction depends on application
  • Please see our Insert Chart to confirm fitment for your application
      • Kit Includes:
    • Low-Volume Insert Tube
    • End-cap collar
    • Set screw

*If you have any questions about fitment or applications, please call our Sales Department at 1-800-634-9166.

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 (5.0 / 5 · 5 reviews)

Emily ★★★★★

The 94db rating is spot on for my RS-4 turn-out end cap—quieter than the stock setup but still has a solid bark. Kit fit the 1.375" opening without any fuss, and the non-spark arrested design was exactly what I needed for my trails.

Elizabeth ★★★★★

I swapped out the stock baffle on my RS-4 muffler and this insert dropped right in—the 1.375" diameter fit perfectly. At idle it’s noticeably quieter, but under throttle you still get that crisp bark without rattling the neighbors. Great for tracks with strict sound limits.

Madison ★★★★★

Bolted these into my RS-4 turn-out end cap and the 94db rating is spot on, took the edge off without killing the tone. Fit was perfect on the 1.375" opening, no rattling even after a couple of hard rides.

Related Products