Replacing a Button Head Cap Screw on Your Exhaust

By Yoshimura R&D of America, Inc. | Published: 2026-10-21

Category: How-to Guides

Learn how to safely replace a 5mm button head cap screw on your Yoshimura exhaust. Step-by-step instructions, common mistakes, and when to call for help.

Quick answer

Replacing a button head cap screw on your Yoshimura exhaust is straightforward with the right tools and technique. You'll need a 3mm hex key, a replacement 5mm x 10mm button head cap screw, and careful alignment to avoid cross-threading.

Why you might need to replace this screw

Button head cap screws on motorcycle exhausts can loosen from vibration, corrode from road salt and moisture, or become damaged during removal. A missing or stripped screw can cause exhaust leaks, rattling, or even loss of a heat shield or bracket. Replacing it early prevents further damage and keeps your exhaust secure.

What you'll need

You'll need a 3mm hex (Allen) key—preferably a T-handle for better torque control—and a replacement 5mm x 10mm button head cap screw. Yoshimura stocks these exact screws as service parts, so you know the thread pitch and length match your system. A small amount of anti-seize compound is optional but recommended for future removal.

Step-by-step replacement process

1. Locate the screw and inspect the area: Identify the button head cap screw that needs replacement. Check the surrounding threads and mounting surface for damage, rust, or debris. Clean the area with a rag and, if needed, a small wire brush. Common mistake: Trying to install a new screw into dirty or damaged threads. Always clean first.
2. Remove the old screw: Insert a 3mm hex key fully into the screw head. Turn counterclockwise steadily. If the screw is stuck, apply penetrating oil and wait 5 minutes. Do not force it—stripping the hex socket is common. Checkpoint: If the hex key slips, stop. Use a screw extractor set or contact a professional to avoid damaging the exhaust.
3. Prepare the new screw: Apply a small dab of anti-seize compound to the threads of the new 5mm x 10mm button head cap screw. This prevents galling and makes future removal easier. Do not overtighten—hand-tighten first. Common mistake: Using too much anti-seize can attract dirt. A thin coating is enough.
4. Install the new screw: Start the screw by hand, turning clockwise until you feel the threads engage. Use the hex key to turn it until snug. Do not apply full torque until you confirm the screw is straight. Checkpoint: If you feel resistance early, back the screw out and realign. Cross-threading ruins the exhaust boss.
5. Tighten to spec: Tighten the screw to approximately 3-4 ft-lb (4-5 Nm) using a torque wrench with a hex bit. If you don't have a torque wrench, tighten until snug plus a quarter turn. Over-tightening can strip the threads or crack the mounting tab. Common mistake: Guessing torque. A small torque wrench is inexpensive and prevents damage.

Product facts

5mm x 10mm BUTTON HEAD CAP SCREW: 5mm x 10mm button head cap screw sold as a replacement service part by Yoshimura. Using the exact OEM-size screw ensures proper thread engagement and avoids damaging the exhaust's threaded boss.
5mm x 10mm BUTTON HEAD CAP SCREW