1998 Johnson Evinrude "EC" 9.9 thru 30 HP 2-Cylinder Outboards Service Manual, Page 148Get this manual
Inspection
1Before any inspection process can begin, all internal components must be clean and free of excess oilRefer to Cleaning, this section
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
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 dimensions5Use OMC Cylinder Bore Gauge, PIN 771310, 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