1994 Johnson/Evinrude "ER" 9.9 thru 30 outboards Service Manual, Page 159Get this manual
1221 9 the piston in two locations, 90 apart from each other, 's In(3 mm) above the bottom of the piston skirt
10The difference between the two measurements is the out-ofroundness and must be no more than 0.002 in(0,05 mm)
1 11 Place each 23
ring, separately, in its respective boreUse piston to square the ring in the cylinderUse feeler gauge to measure the ring end gap The ring gap (0,13-0,38 mm)must be within
0.005-0.015 in
1241 12Use 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 The side clearance (0,10 mm)must not exceed