Yamaha OEM NLA NOS 

 2- 2K6-11631-00-97  STD PISTONS

  2- 2K6-11635-00 1ST OVER PISTON  .020MM OVER  

2- 2K6-11636-00 2ND OVER PISTON .050 MM OVER 

1-2K6-11637-00 3rd (0.75) over piston  .075 MM OVER  

   FITS 1978 YZ125, 1979YZ125 & 1980 YZ125