ORIGINAL FITS 1962 YAMAHA PISTONS YDS2, 1962-1964YD3, 1963 YDT1
2- 150-11631-0Z/ 150/11637-10 56.75MM 3RD OVER PISTONS
3- 150-11631-0Z/150-11638-00 57.00MM 4TH OVER PISTONS
PISTON MEASUREMENT SUGGESTED