1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 204Get this manual
CYLINDER BLOCKCRANKCASE
Crankcase and Bearing
1Measure crankshaft main bearing clearance using the test below, replace the bearings as set if out of specification (see Crankcase and Bearing Indication Marks)Main Bearing Clearance 0.00040.0015 in(0.0110.039 mm) CRANKSHAFT MAIN BEARING CLEARANCE MEASUREMENT IMPORTANT: Do not interchange the main bearingsReinstall in their original position1Clean all the old sealing material from the split line on the crankcase cover and cylinder block2Clean all the oil from the following areas: Main bearing surfaces on the cylinder block and crankcase coverMain bearingsCrankshaft bearing surfaces