How to Replace the End Cap on Your Yoshimura RS-9 Muffler

By Yoshimura R&D of America, Inc. | Published: 2026-10-17

Category: How-to Guides

Step-by-step guide to replacing the left-side end cap on your Yoshimura RS-9 or RS-9T muffler, including tools, tips, and common mistakes to avoid.

Quick Answer

To replace the end cap on your Yoshimura RS-9 or RS-9T left-side muffler, you'll need a replacement end cap kit, a rivet gun, and basic hand tools. The process involves removing the old rivets, swapping the cap, and securing the new one with the included hardware. Allow about 30 minutes and take care not to damage the carbon fiber.

What You Need and Why It Matters

Before you start, gather a rivet gun, a drill with a small bit (around 3mm) to remove old rivets, a punch or awl, safety glasses, and a clean work surface. The replacement end cap kit includes the carbon fiber cap, decal set, rivets, and a sound insert hole grommet, so you won't need to source extra parts. Using the correct rivet size is critical—too long and they may protrude inside the muffler; too short and they won't hold securely.

Inspect Before You Swap

Check the condition of the muffler body and the existing end cap. If the cap is cracked or the carbon fiber is delaminating, replacement is the right call. But if the muffler itself has a hole or severe damage, a new sleeve or muffler might be more cost-effective. For minor scuffs, you might not need a full replacement—just a careful cleaning.

Step-by-Step Replacement Process

Secure the Muffler: Remove the muffler from the bike or clamp it securely to a workbench. Make sure it's stable and won't rotate while you work. This prevents accidental damage to the carbon fiber or the mounting tabs. Checkpoint: The muffler should not move when you apply pressure.
Remove the Old End Cap: Use a drill with a small bit to carefully drill out the center of each rivet. Then use a punch to push the rivet bodies out. Work slowly to avoid enlarging the holes in the muffler body. Common mistake: Drilling too deep can damage the inner baffle. Stop as soon as the rivet head pops off.
Clean the Mating Surface: Wipe the area where the new end cap will sit with a clean, dry cloth. Remove any old sealant, debris, or loose carbon fiber. A clean surface ensures a tight fit and prevents rattles. Checkpoint: The surface should be smooth and free of residue.
Install the New End Cap: Place the new carbon fiber end cap onto the muffler, aligning the sound insert hole with the corresponding opening. Insert the grommet into the hole if it's not already pre-installed. Ensure the cap sits flush and the decal orientation is correct. Common mistake: Forcing the cap can crack the carbon fiber. If it doesn't seat easily, check for obstructions.
Secure with Rivets: Insert the provided rivets through the cap and into the muffler holes. Use a rivet gun to set each rivet, working evenly around the cap. Apply steady, even pressure to avoid pulling the cap out of alignment. Checkpoint: All rivets should be snug and the cap should not move when you push on it.
Apply the Decal Set: Clean the new end cap surface with a mild solvent or alcohol wipe. Apply the included decals according to the instructions, using a squeegee to remove air bubbles. Let the decals cure for at least 24 hours before washing or riding in heavy rain. Common mistake: Applying decals over dust or oil will cause them to peel. Take your time to position them symmetrically.

Product Facts

RS-9 / RS-9T REPLACEMENT END CAP KIT LEFT SIDE: Fits all RS-9, 9T LEFT side mufflers. Made in our composites shop in Chino California with heat resistant pre-impregnated, high gloss lightweight carbon fiber. This replacement carbon fiber end cap kit has all the parts you need to do an end cap swap. Kit includes: High-gloss left side carbon fiber end cap, End-cap Decal Set, Rivets, Sound Insert hole grommet. This kit is specifically designed for the left side of RS-9/9T mufflers, ensuring a proper fit and matching finish. The included rivets and grommet mean you won't have to buy extra hardware, saving time and ensuring a secure installation.