Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 155Get this manual
Crankshaft 1Thoroughly clean crankshaft and inspect bearing surfacesReplace crankshaft in bearing surfaces are pitted, scored, or discolored2Measure crankshaft main bearing journals, connecting rod journals, and crankshaft width (see specifications)Replace crankshaft if out of specifications3Measure RunoutOut of specification, replace
4Place piece of plastigauge onto the crankshaft bearing surface
5Install crankcase coverApply oil to the cover bolts and torque cover bolts in sequence and in two steps1 Crankshaft Runout 0.0008 in(0.02 mm) 10
Checking Main Bearing Clearance
IMPORTANT: Do not interchange the main bearingsThey must be installed in their original position1Clean all the oil from the crankshaft bearing surfaces and main bearings