Mercury Mariner 4, 5, and 6HP 4-Stroke Factory Service Manual, Page 157Get this manual
CYLINDER BLOCK AND CRANKCASE
Measuring Diameter of Crank Pin "A"
Standard Value 1.179 in(29.94 mm) Out of the Limit If 1.177 in(29.91 mm) or less requires replacement
Measuring Outer Diameter of Crankshaft in the Oil Pan Bearing "B"
Standard Value 0.983 in(24.98 mm) Out of the Limit If 0.982 in(24.96 mm) or less requires replacement