1993 Johnson Evinrude "ET" 9.9 thru 30 Service Manual, P/N 508282, Page 177Get this manual
Inspection
1Before any inspection process can begin, all internal components must be clean and free of excess oilRefer to Cleaning, this Section2Make visual inspection of all internal componentsCheck for unusual wear patterns, scuffing or deterioration of aluminum parts, heat-related discoloration of bearings or bearing surfaces, and broken components403Check for cylinder head warpage using piece of bar stock or machinist's straightedge and feeler gauge set Cylinder head warpage must not exceed 0.004 in(0,10 mm) end to endResurface or replace head if warpage exceeds this dimension4Use micrometer to measure the diameter of each crankpin and main bearing journalThe lower main bearing journal would only be measured if the bearing was removed for another reasonRefer to Engine Specifications, Section 1, for dimensionsf41l5Use telescoping gauge or inside reading micrometer to inspect each cylinder bore for an out-of-round, oversize, or tapered conditionBe sure the gauge or micrometer is perfectly square in the bore when measuring4216Measure each cylinder in at leasttwo areas as shownEach area should be measured twiceThe difference between the two measurements in each area is the cylinder out-of-round dimension The cylinder must not be out-of-round by more than 0.003 in(0,08 mm)7The dimensional difference between the two areas is cylinder taper The cylinder taper must not exceed 0.002 in(0,05 mm) 8The difference between your measurements and standard bore dimension is cylinder oversizeRefer to Engine Specifications, Section 1, for dimensions The cylinder must not be oversize by more than 0.003 in(0,08 mm)If any cylinder is outside these tolerances, it must be bored oversizeOne oversize piston is available for this engine (0.030 in0,762 mm)To determine oversize bore, add 0.030 in(0,762 mm) to the standard boreRefer to Engine Specifications, Section 1It is permissible to have one or more oversize pistons in an engine