Mercury 225 EFI, Service Manual

Page: 364 / 719

POWERHEAD
Page 4A-52 90-884294 OCTOBER 2001
Crankshaft (and End Cap) Bearings
IMPORTANT: When overhauling powerhead assembly, it is recommended that all
crankshaft bearings – upper/lower, center main, connecting rod and wrist pin bear-
ings – be replaced to ensure optimum powerhead performance and longevity.
1. After cleaning crankshaft, grasp outer race of crankshaft ball bearing (installed on lower
end of crankshaft) and attempt to work race back-and-forth. There should not be exces-
sive play.
2. Lubricate ball bearing with light oil. Rotate outer bearing race. Bearing should have
smooth action and no rust stains. If ball bearing sounds or feels “rough” or has “catches,”
remove and discard bearing. (Refer to “Powerhead Removal and Disassembly - Crank-
shaft Removal and Disassembly”.)
a
52326
a - Lower Crankshaft Ball Bearing
3. Thoroughly clean (with solvent) and dry crankshaft center main roller bearings. Lubri-
cate bearings with 2-Cycle Outboard Oil.
CAUTION
DO NOT intermix halves of upper and lower crankshaft center main roller bearings.
Replace bearings in pairs only.
4. Thoroughly inspect center main roller bearings. Replace bearings if they are rusted,
fractured, worn, galled or badly discolored.
52153
a
a - Center Main Roller Bearing
5. Clean (with solvent) and dry crankshaft roller bearing that is installed in upper end cap.
Lubricate bearing with light oil.
6. Thoroughly inspect upper crank shaft roller bearing. If roller bearing is rusted, fractured,
worn, galled, badly discolored or loose inside of end cap replace end cap and roller bear-
ing as an assembly.
a
a - Upper Roller Bearing