Checking Main Bearing Clearance - Mercury 40 Service Manual

CYLINDER BLOCK/CRANKCASE
Crankshaft
1. Thoroughly clean crankshaft and inspect bearing surfaces. Replace crankshaft if bear-
ing surfaces are pitted, scored, or discolored.
2. Measure Run-out. Replace crankshaft if out of specification.

Checking Main Bearing Clearance

IMPORTANT: Do not interchange the main bearings. Reinstall in their original posi-
tion.
1. Clean all the old sealing material from the split line on the crankcase cover and cylinder
block.
2. Clean all the oil from the following areas:
NOTE: Refer to instructions in Cylinder Block Reassembly for selecting and installing main
bearings.
3. Install main bearings.
4. Place crankshaft into cylinder block.
Page 4B-22
Crankshaft Run-out
0.0012 in. (0.03 mm)
Main bearing surfaces on the cylinder block and crankcase cover.
Main bearings.
Crankshaft bearing surfaces.
53811
90-828631R3 MARCH 1999