1997 Johnsoon Evinrude "EU" 50 thru 70 3-Cylinder Service Manual, P/N 507266, Page 154Get this manual
Inspection 1Before any inspection process can begin, all internal components must be clean and free of excess oil 2Make 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
3Check 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
rn 4Use main bearingtojournalThethe diameter of each micrometer measure crankpin and lower main bearing
journal would only be measured if the bearing was removed for another reasonRefer to Engine Specifications, Section 1, for dimensions
5Use 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