At DMG Motorsports, we present the Yoshimura RS-4 Exhaust Quiet Insert 1.25" (INS-13-K) — a genuine Yoshimura replacement part built to bring your RS-4 slip-on muffler into compliance with strict track and trail sound requirements without you having to buy a whole new exhaust system. Riders running a Yoshimura RS-4 system know that different tracks, series, and riding areas call for different decibel limits, and this factory insert kit is the simple, bolt-in solution to help you meet those limits while keeping your Yoshimura muffler on the bike.

Designed and engineered by Yoshimura specifically for their RS-4 muffler line, this 1.25" insert swaps in for your stock core to quiet things down for sound-restricted events, neighborhood-friendly riding, or noise ordinance compliance. It's a straightforward, no-fuss upgrade that lets you keep the performance and look of your Yoshimura exhaust while dialing back the volume when you need to.

Features:

• Genuine Yoshimura replacement Low-Volume Insert Kit engineered specifically for Yoshimura RS-4 mufflers
• Non-spark arrested insert available as an optional kit on applications requiring different sound restrictions
• Decibel reduction depends on the specific application and muffler setup
• 1.25" (1.250") diameter insert tube sized to fit compatible RS-4 muffler outlets
• Helps make your Yoshimura exhaust system or slip-on muffler meet AMA Pro sound requirements
• Kit includes low-volume insert tube, end-cap collar, and set screw for a complete, easy installation
• Direct-fit factory replacement part, sold each, for use with compatible Yoshimura RS-4 applications
• Backed by Yoshimura's decades of racing-proven exhaust engineering and quality