Hello, I've just opened the top-end for checking everything against measurements and tolerances like shown in the workbook and found that the cylinder is not in the condition I liked it to be to be honest; The bike has 5645Km with 252 hrs and a bought it second hand so I cannot be 100% sure about the hrs or kms... I've measured cylinder and piston with a precise micrometer getting the following results (all in milimeters): Maximum cylinder measure (measured 6 times X and Y like shown in the book): 95,04 (should be 95,00-95,01 so it is off ) Minimum cylinder measure: 95,03 Ovalization: 0,01 (maximum 0,05) Conicity: 0,01 (maximum 0,05) Piston diameter at 8mm from skirt: 94,98 (specified is 94,965 - 94,980) Clearance piston/cylinder 95,04-94,98= 0,06 (Standard is 0,020 - 0,045 with service limit of 0,1 so it is ok) The rings are also within the tolerances. First ring gap: 0,40 (standard 0,20 - 0,30 with limit 0,55) Second ring gap: 0,70 (standard 0,35 - 0,50 with limit 0,85) Here some fotos of the cylinder and piston: What do you think ? Is it normal having this signs of wornout in the cylinder with only 5600 Km ??? The measures are all within the tolerances and should not give any problems leaving it untouched but the cylinder is off and the nikasil is not in it best shape, you cannot see the marks of the honing in the longitudinal axis at all and there ARE some vertical scratches that you CAN feel with the nail... I think the correct thing is to replate or going for an exchange cylinder, what do you think ? Thanks and best regards from Spain.