1986 2001 Honda 270 Bore and Stroke Sheet
BoreSize
66.40 = Standard
66.65 = .010 O/B
66.90 = .020 O/B
67.01 = .024 O/B
67.16 = .030 O/B
67.28 = .035 O/B
67.41 = .040 O/B
67.51 = .044 O/B
67.67 = .050 O/B
67.92 = .060 O/B
68.05 = .065 O/B
68.17 = .070 O/B
68.43 = .080 O/B
68.55 = .085 0/B
68.68 = .090 O/B
68.81 = .095 O/B
68.94 = .100 O/B
69.06 = .105 O/B
69.19 = .110 O/B
Stroke 2mm.= .080=.040up,.040down
Stroke 4mm = .160=.080up,.080down
Bore Squared x Stroke x 3.14159 = divided by 4000 = Your Motor C
72mm----66.40 = 249.320cc Stock
72mm----66.65 = 251.201cc .010 o/s
72mm----66.90 = 253.089cc .020 o/s
72mm----67.01 = 253.922cc .024 o/s
72mm----67.16 = 255.060cc .030 o/s
72mm----67.28 = 255.973cc .035 o/s
72mm----67.41 = 256.963cc .040 o/s
72mm----67.51 = 257.726cc .044 o/s
72mm----67.67 = 258.949cc .050 o/s
72mm----67.92 = 260.866cc .060 o/s
72mm----68.05 = 261.865cc .065 o/s
72mm----68.17 = 262.790cc .070 o/s
72mm----68.43 = 264.798cc .080 o/s
72mm----68.55 = 265.727cc .085 o/s
72mm----68.68 = 266.736cc .090 o/s
72mm----68.81 = 267.747cc .095 o/s
72mm----68.94 = 268.760cc .100 o/s
72mm----69.06 = 269.696cc .105 o/s
72mm----69.19 = 270.712cc .110 o/s
74mm----66.40 = 256.246cc Stock
74mm----66.65 = 258.179cc .010 o/s
74mm----66.90 = 260.120cc .020 o/s
74mm----67.01 = 260.976cc .024 o/s
74mm----67.16 = 262.145cc .030 o/s
74mm----67.28 = 263.083cc .035 o/s
74mm----67.41 = 264.101cc .040 o/s
74mm----67.51 = 264.885cc .044 o/s
74mm----67.67 = 266.142cc .050 o/s
74mm----67.92 = 268.112cc .060 o/s
74mm----68.05 = 269.139cc .065 o/s
74mm----68.17 = 270.089cc .070 o/s
76mm----66.40 = 263.171cc Stock
76mm----66.65 = 265.157cc .010 o/s
76mm----66.90 = 267.150cc .020 o/s
76mm----67.01 = 268.029cc .024 o/s
76mm----67.16 = 269.230cc .030 o/s
76mm----67.28 = 270.193cc .035 o/s
76mm----67.41 = 271.238cc .040 o/s