Arrow Thunder Slip-On Rear Muffler Yamaha WR 125, model year 2026 and later, with EC type approval, steel end cap

The Arrow Thunder Slip-On muffler was developed specifically for the Yamaha WR 125 R and replaces the stock muffler while retaining the stock exhaust headers. The Thunder series combines a sporty look with a compact design and high-quality craftsmanship.

The muffler features a dark aluminum outer shell and a stainless steel end cap. Thanks to the slip-on design, the original exhaust system remains intact. The rear silencer is street-legal and comes with mounting hardware.

Technical Specifications

• Manufacturer: ARROW
• Model: Thunder
• Type: Slip-On Rear Muffler
• Silencer material: Dark aluminum
• End cap material: Stainless steel
• Inner material: Stainless steel
• Connecting pipe material: Stainless steel
• Mounting: Welded bracket
• Muffler length: 350 mm
• Inlet connection diameter: 35 mm
• Connection diameter (outlet): 45 mm
• CO sensor connection: No
• Lambda probe connection: No
• dB killer: Yes
• Position: Standard
• Homologation: Street legal
• Part number: 52513AON

Fits:

• Yamaha WR 125 R, model year 26-

Note

• Euro 5+ vehicle with dual lambda sensors
• When using Arrow headers or connecting pipes, an engine warning light may appear
• dB-killer permanently welded

Included

• 1x Arrow Thunder Slip-On muffler
• Connecting pipe
• Mounting brackets and hardware
• Installation instructions