Yoshimura 1.625 in RS-12 Exhaust Sound Insert INS-31-K

The Yoshimura INS-31-K is a replacement low-volume insert kit for RS-12 mufflers. Designed for applications requiring different sound restrictions, this insert supports Yoshimura exhaust performance and provides decibel reduction that depends on the specific application.

This insert is non-spark arrested and fits the 2026 Yamaha YZ250F and 2026 Kawasaki KX250. Manufacturer part number: INS-31-K. Vendor part number: INS-31-K.

Features:

• Replacement low-volume insert kit for Yoshimura RS-12 mufflers
• 1.625-inch insert size
• Available as an optional kit for applications requiring different sound restrictions
• Decibel reduction depends on the application
• Non-spark arrested
• Fits 2026 Yamaha YZ250F and 2026 Kawasaki KX250