Chrysler 20 and 30 HP Outboard Motors Service Manual OB 3435, Page 146Get this manual
DIf cylinder walls are glazed, break the glaze by honing with medium stone, 220 grit NOTE Glaze reduces the effectiveness of the seal between the piston rings and cylinder walls DIAL INDICATOR OR INSIDE MICROMETER
ECheck bearing surfaces inside crankcase Temporarily install crankcase cover on cylinder block to measure wear on crankshaft bearing surfacesTighten bearing bolts to 160 in Ibs(183 5kg cm) torque7Check crankshaft as follows :
ACheck threads on end of crankshaft for damageRepair with 12"20 dieBInspect keyway and tapered ends of shaft for scoringwearCCheck ball bearing for restricted movement, cracks and wearDMeasure crankshaftFigure 38Measuring Cylinders
8Check connecting rods as follows :
BReplace cylinder block if wear is more than .002" (0.05 mm) or if cylinder is out of roundCIf cylinder is within wear tolerance, but slightly scored, hone with fine stone cylinder honeFigure 39
AMeasure both ends of connecting rods with inside micrometer