JE Pistons 221781 FSR Forged Piston Kit 95mm 12.5:1 Compression Motorcycle

The JE Pistons 221781 is a high-performance FSR (Forged Side Relief) forged piston kit engineered for motorcycle engines. Built to a 95.00mm standard bore with a 12.5:1 compression ratio, this piston kit delivers the race-proven precision and durability that JE Pistons is known for across professional motorsports worldwide.

JE's proprietary FSR forging design reduces skirt width to minimize friction and power loss, while also allowing for a shorter wrist pin for additional weight savings. Every piston is engineered, forged, and machined in the USA to exacting tolerances, ensuring consistent performance in high-demand applications.

Key Features:

• Bore: 95.00mm (standard bore)
• Compression Ratio: 12.5:1
• Smooth radius dome and dish design for optimized combustion
• Radiused valve reliefs for improved flow and clearance
• Precision CNC-machined ring grooves for consistent ring seal
• Machined oil drain-back holes engineered for specific oil control
• Factory-honed pin bores, wrist pins, and locks included
• Proprietary FSR forging minimizes skirt friction and reduces reciprocating weight
• Engineered, forged, and machined 100% in the USA

JE Pistons has built a championship-level reputation across NASCAR, the Indy 500, Baja 1000, SCCA Trans-Am, 24 Hours of Daytona, Le Mans, Paris to Dakar, and many other top-tier racing series. The 221781 piston kit brings that same race-developed technology to your motorcycle engine build.