1991 Johnson/Evinrude EI 60 thru 70 outboards Service Manual, Page 153Get this manual
16l 9Use micrometer to check piston conditionMake at least
two measurements, 90 from each otherMeasure the piston diameter 14 in(6,4 mm) above the bottom edgeRefer to Engine Specifications, Section 1, for piston dimensions The difference between the two piston measurements must not exceed 0.003 in(0,08 mm)
to square the ring in the cylinderUse feeler gauge to measure the ring end gap The ring end gap must be within 0.007-0.017 in(0,130,46 mm)101 11Use feeler gauge to check groove side clearance on the lower, square ringsInstall each square ring on its pistonWith the ring seated in its groove, make several checks around the piston