1993 Johnson Evinrude "ET" 60 thru 70 Service Manual, P/N 508284, Page 150Get this manual
Isl 9Use micrometer to check piston conditionMake at least two measurements, 90 from each otherMeasure the piston diameter V4 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)r:;] 10For new or used ring sets, make the following inspectionsPlace each ring, separately, in its respective boreUse piston 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)
Ial 11Use feeler gauge to check groove side clearance on the