PISTON KIT 87-07 YFZ350 64.50, WISECO 513M06450RD350 82-90

Part no 56-W513+050_WI (phoenixmotos.com)
YAMAHA YFZ 350 BANSHEE 1987-2007,
Yamaha RD350 LC - YPVS (1980-1987),
Yamaha RD350 AC (1950-2014),
Wiseco 64.50mm piston kit

(Wiseco part no 513M06450)