Suzuki DF25/DF30 Four Stroke Service Manual, Page 158Get this manual
POWER UNIT 7-41 Cylinder bore wear (difference) Using cylinder gauge, measure cylinder bore in both axial (Vertical line, following crankshaft) and transverse (horizontal line across crankshaft) direction at two posirions as shown in figure09900-20508Cylinder gauge set Check for followingDifference between measurements at the two positions (taper) Difference between axial and transverse measurement (outof-round)Cylinder bore wear (diferencia) Service limit0.100 mm (0.0039 in If measurement exceeds service limit, rebore or replace cylinder