For your future reference, you can figure out the displacement of any reciprocal internal combustion engine, automoble or motorcycle, by using the folllowing formula (it does not work for rotaries):
1/2 the bore squared (the radius of the cylinder) x the stroke (the height of the cylinder) x pi (3.1416 will do) x the number of cylinders. So, for the C90, with a bore of 96mm and a stroke of 101mm, the displacement would be:
48 x 48 = 2304
2304 x 101= 232,704
232704 x 3.1416 = 731062.8864
convert cubic millimeters to cubic centimeters by dividing by 1,000 = 731.0628864
(This step only necessary where cylinder specs are given in millimeters - if given in centimeters or inches, this step is omitted)
731.0628864 x 2 (number of cylinders) = 1462.1257728 cc
There you have it.