2003 Johnson ST 55 HP WRL 2 Stroke Commercial Service Manual, PN 5005483, Page 134Get this manual
POWERHEAD INSPECTION
INSPECTION
Before any inspection process can begin, all internal components must be clean and free of excess oilMake 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 componentsCheck for cylinder head warpage using piece of bar stock or machinist's straightedge and feeler gauge set Cylinder head warpage must not be more than 0.003 in(0.08 mm) per inch of measurementReplace head if warpage is more than this dimension
Use Cylinder Bore Gauge, PIN 771310, to inspect each cylinder bore for an out-of-roundoversize, or tapered conditionBe sure the gauge or micrometer is perfectly square in the bore when measuring
Cylinder Bore Gauge
Measure each cylinder in at least two areas as shownEach area must 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)The dimensional difference between the two areas is cylinder taper The cylinder taper must not exceed 0.002 in(0.05 mm)