1993 Johnson Evinrude "ET" 40 thru 55 Service Manual, P/N 508283, Page 161Get 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 components
f213Check 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 dimension
4Use micrometer to measure the diameter of each crankpin and main bearing journalThe lower main bearing journal would only be measured ifthe bearing was removed for another reasonRefer to Engine Specifications, Section 1, for dimensions
Use 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 measuring