http://www.x-h2o.com/index.php?threads/yamaha-62t-61x-displacement-vs-bore-stroke-combinations.5136/
Displacement vs. Bore and Stroke Combinations for Yamaha 62T/61X-Based Motors
All bore and stroke units in millimeters (mm)
Bore OEM cc +4mm cc +5mm cc +6mm cc +8mm cc +10mm cc
81.0 68 701 72 742 73 752 74 763 76 783 78 804
81.5 68 709 72 751 73 762 74 772 76 793 78 814
82.0 68 718 72 760 73 771 74 782 76 803 78 824
82.5 68 727 72 770 73 780 74 791 76 813 78 834
83.0 68 736 72 779 73 790 74 801 76 822 78 844
83.5 68 745 72 789 73 799 74 810 76 832 78 854
84.0 68 754 72 798 73 809 74 820 76 842 78 865
84.5 68 763 72 808 73 819 74 830 76 852 78 875
85.0 68 772 72 817 73 828 74 840 76 863 78 885
85.5 68 781 72 827 73 838 74 850 76 873 78 896
86.0 68 790 72 836 73 848 74 860 76 883 78 906
86.5 68 799 72 846 73 858 74 870 76 893 78 917
87.0 68 808 72 856 73 868 74 880 76 904 78 927
87.5 68 818 72 866 73 878 74 890 76 914 78 938
88.0 68 827 72 876 73 888 74 900 76 924 78 949
88.5 68 837 72 886 73 898 74 910 76 935 78 960
89.0 68 846 72 896 73 908 74 921 76 946 78 970
89.5 68 856 72 906 73 919 74 931 76 956 78 981
90.0 68 865 72 916 73 929 74 942 76 967 78 992
90.5 68 875 72 926 73 939 74 952 76 978 78 1003
91.0 68 885 72 937 73 950 74 963 76 989 78 1015
91.5 68 894 72 947 73 960 74 973 76 999 78 1026
92.0 68 904 72 957 73 971 74 984 76 1010 78 1037