1999 "EE" Evinrude 200, 225 V6 FFI Outboards Service Manual, P/N 787025, Page 166Get this manual
[] 10Use micrometer to check piston conditionMake at least two measurements, 90 from each otherMeasure the piston diameter 1f4 in(6,4 mm) above the bottom edge Refer to Engine Specifications, Section 2, for piston dimensions The difference between the two piston measurements must not exceed 0.004 in(0,10 mm)[] 11For the new 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 0.0190.031 in(0,48 0,79 mm)[] 12Use machinist's straightedge to check clearance on tapered piston ringBoth rings are taperedWhen checked with the straightedge, there should be enough ring clearance to allow the straightedge to touch the piston on both sides of the ring grooveMake several checks around the piston If straightedge does not touch piston, remove the ring and clean the ring groove