1987-1999 Yamaha YFM 350 Big Bear ATV Engine Piston Ring Kit [Bore Size (mm): 82.95 (Stock)] Bore Size (mm): 82.95 Ring Kits Include Piston Rings Only - Piston Not Included Namura Piston Rings Fit Both Namura and OEM Pistons of the Same Bore Size Unless Otherwise Specified Compatibility: 1987-1999 Yamaha YFM 350 Big Bear