Yoshimura RS-9 Carbon Fiber End Cap Cover: When and How to Replace It

Quick answer

Replace your RS-9 carbon fiber end cap cover when you see cracks, delamination, loose rivets, or heat damage that a decal refresh cannot hide. Order the RS-9 / RS-9T Replacement End Cap Kit Left Side, drill out the old rivets, transfer the sound insert grommet, and rivet the new high-gloss carbon cap in place. The job takes about 30 to 45 minutes with basic hand tools.

Your RS-9 muffler's carbon fiber end cap takes the brunt of heat, road debris, and repeated wash cycles. Over time the clear coat dulls, rivet holes elongate, or the carbon layers start to separate at the edge. A worn end cap is not just cosmetic — loose rivets can let the cap vibrate, and a cracked edge can trap moisture against the muffler body.

This guide walks through the decision points and the actual swap. It covers when a replacement is the right call versus when a decal refresh is enough, what the RS-9 / RS-9T Replacement End Cap Kit Left Side includes, and the step-by-step process to install it without damaging the muffler sleeve or the sound insert hardware.

When a carbon fiber end cap cover actually needs replacing

Not every scuff or faded spot means you need a new cap. Surface scratches in the clear coat, light discoloration from heat, or a peeling decal are cosmetic issues you can often live with or fix with a decal set. The replacement decision changes when the damage is structural: cracks that run through the carbon weave, delamination where layers lift at the edge, elongated or torn rivet holes, or a cap that moves when you push on it.

Heat damage is the other trigger. Carbon fiber is heat resistant, but the resin system has limits. If the cap has turned chalky white or gray in a concentrated area near the outlet, the resin is breaking down. That is not something polish fixes. At that point, a new cap is the safer choice because a failing cap can eventually separate from the muffler at speed.

• Check the rivet holes first — elongation is the clearest sign the cap has been moving and needs replacement.
• If only the decal is damaged, a decal set is far cheaper than a full cap kit.

What the RS-9 replacement end cap kit includes

The RS-9 / RS-9T Replacement End Cap Kit Left Side is made in the composites shop in Chino, California, using heat-resistant pre-impregnated, high-gloss lightweight carbon fiber. It fits all RS-9 and RS-9T left-side mufflers. The kit is designed as a complete swap package, not just a bare cap, so you are not hunting for individual small parts.

Inside the kit you get the high-gloss left-side carbon fiber end cap, an end-cap decal set, rivets, and the sound insert hole grommet. That grommet matters more than people expect — it seals the opening where the sound insert passes through, and reusing a hardened or torn grommet can cause a rattle or an exhaust leak at the cap. Because the kit includes it, you replace it at the same time as the cap.

• Confirm you have the left-side cap before drilling anything — the kit is side-specific.
• If your muffler uses a sound insert, keep the old insert tube; the kit supplies the grommet, not the insert itself.

Tools and prep before you drill

You need a drill with a bit sized to the rivet heads, a rivet gun, a center punch, safety glasses, and a soft cloth or tape to protect the muffler sleeve. Work on a clean bench or a stable surface with the muffler supported so it does not roll while you drill. Let the exhaust cool completely if the bike was recently run — carbon fiber holds heat and the metal underneath stays hot longer than you expect.

Before drilling, mark the orientation of the old cap relative to the muffler outlet. A paint pen or a strip of masking tape across the cap-to-sleeve seam gives you a reference line. This matters because the new cap needs to sit in the same clock position so the sound insert hole and decal line up correctly. Skipping this step is the most common reason a fresh cap ends up looking crooked.

• Wear eye protection — drilling rivets throws small metal fragments.
• Photograph the cap before removal so you can match decal placement on the new one.

Step-by-step: removing the old end cap

Start by drilling the rivet heads. Use a bit slightly larger than the rivet shank and drill only until the head pops off — do not drive through into the carbon or the muffler sleeve. A center punch mark keeps the bit from walking. Once the heads are off, push the rivet tails out with a pin punch and pull the old cap away from the muffler body. If the cap is stuck from heat cycling, work it gently side to side rather than prying at the edge.

With the cap off, inspect the muffler outlet and the rivet holes in the sleeve. Clean any carbon buildup or old sealant from the mating surface. If the sleeve holes are elongated, note that — you may need slightly larger rivets or a backing washer, and that is a good time to call Yoshimura at 800-634-9166 to confirm the right hardware for your application.

• Do not reuse old rivets — they are a one-time fastener and will not hold torque after removal.
• If the old grommet crumbles when removed, that confirms the kit's new grommet was necessary.

Installing the new carbon fiber cap

Fit the new grommet into the sound insert hole in the cap before you mount anything. Then align the new cap using your reference marks and press it onto the muffler outlet. Check the sound insert hole alignment by test-fitting the insert tube through the grommet — it should pass cleanly without forcing. If it binds, rotate the cap slightly until it seats. Only after alignment is confirmed should you start riveting.

Rivet in a star pattern rather than going around the circle in order. This pulls the cap down evenly and prevents one side from lifting while you work the other. Use a rivet gun with steady pressure and let each rivet set fully before moving to the next. Once all rivets are in, push on the cap edge — any movement means a rivet did not set properly and needs to be drilled and replaced.

• Test-fit the sound insert before riveting — after the rivets are set, alignment is locked in.
• A wobble or gap at the seam means stop and re-check before adding more rivets.

Decals, care, and keeping the carbon looking new

Apply the end-cap decals last, after the cap is fully secured. Clean the carbon surface with isopropyl alcohol and let it dry completely before placing decals — any oil or dust shortens their life. Use the photos you took earlier as a placement guide. Press from the center outward to push out air bubbles, and avoid stretching the decal around curves.

For ongoing carbon fiber end cap maintenance, wash with mild soap and water and avoid harsh solvents or abrasive polishes that cut through the clear coat. A UV-protectant spray designed for carbon or painted surfaces helps slow fading. Check the rivets every few rides — a quick push test takes seconds and catches a loose cap before it becomes a bigger problem. If you ever lose a rivet or need a replacement decal set, the MUFFLER BADGE RS-12 ADV End Cap Decal Set (3 pcs) shows the kind of small replacement parts Yoshimura stocks, though it is specific to the RS-12 ADV end cap.

• Never use brake cleaner or acetone on the carbon cap — it attacks the resin and clear coat.
• Re-torque check is not applicable to rivets; use a visual and push test instead.

RS-9 end cap replacement checklist

1. Confirm left-side fitment and kit contents: Verify your muffler is an RS-9 or RS-9T left side and that the kit includes the cap, decals, rivets, and sound insert grommet. Wrong side or missing grommet means a second order and a stalled job.
2. Mark cap orientation before drilling: Use masking tape or a paint pen across the cap-to-sleeve seam to record clock position for the sound insert hole and decal line. Skipping this is the top cause of a crooked-looking new cap.
3. Drill rivet heads only, then punch out tails: Use a bit slightly larger than the rivet shank, drill until the head pops, and push the tail out with a pin punch. Do not drill into the carbon or sleeve. If the bit walks, stop and re-center punch before continuing.
4. Fit the new grommet and test the sound insert: Install the grommet in the new cap, align the cap, and pass the insert tube through to confirm it seats without forcing. Binding means rotate the cap before riveting — alignment locks once rivets are set.
5. Rivet in a star pattern and push-test the edge: Set rivets across from each other rather than around the circle, then push on the cap edge to check for movement. Any wobble means drill that rivet and reset it before moving on.
6. Clean and apply decals last: Wipe the carbon with isopropyl alcohol, let it dry, and place decals using your earlier photos as a guide. Decals applied over oil or dust peel early — clean first, place once.

Parts that make this job easier

• RS-9 / RS-9T REPLACEMENT END CAP KIT LEFT SIDE: Fits all RS-9 and RS-9T left-side mufflers. Made in the composites shop in Chino, California, with heat-resistant pre-impregnated, high-gloss lightweight carbon fiber. Kit includes the high-gloss left-side carbon fiber end cap, end-cap decal set, rivets, and sound insert hole grommet. The kit bundles every wear item you touch during a swap, so you are not reusing a hardened grommet or hunting for matching rivets mid-job.
• MUFFLER BADGE RS-12 ADV End Cap Decal Set (3 pcs): RS-12 ADV replacement end-cap decal 3-piece set: 2 outward facing decals and 1 inward facing decal. This is the end-cap decal set only; the badge on the muffler sleeve is sold separately as RS12-NB006. If your cap is structurally fine but the decals are scuffed, a decal set is a low-cost cosmetic fix — but confirm it is the right part number for your muffler before ordering.

A carbon fiber end cap cover is a wear item, and treating it like one keeps your RS-9 looking sharp and structurally sound. Replace it when you see cracks, delamination, or loose rivets rather than waiting for the cap to fail on the road. The RS-9 / RS-9T Replacement End Cap Kit Left Side gives you the cap, decals, rivets, and grommet in one package, and the swap is a straightforward bench job if you mark orientation first and rivet in a star pattern.