Mercury 200 OptiMax Jet Drive, Service Manual, Page: 308 / 391

Powerhead
90-8M0050731 MAY 2011 Page 4A-43
4. Thoroughly inspect the center main roller bearing. Replace the bearings if they are rusted, fractured, worn, galled, or badly
discolored.
a - Center main roller bearing
5. Clean and dry the crankshaft roller bearing that is installed in the upper end cap. Lubricate the bearing with 2‑Cycle Premium
Outboard Oil.
Tube Ref No. Description Where Used Part No.
14
2-cycle Premium
Outboard Oil
Main bearings 92-858021K01
6. Thoroughly inspect the upper crankshaft roller bearing. If the roller bearing is rusted, fractured, worn, galled, badly discolored,
or loose inside of the end cap, replace the end cap and roller bearing as an assembly.
a - Upper roller bearing
Connecting Rods
1. Check the connecting rods for alignment by placing the rods on a surface plate. If light can be seen under any portion of the
machined surfaces, if the rod has a slight wobble on the plate, or if a 0.051 mm (0.002 in.) feeler gauge can be inserted
between any machined surface and surface plate, replace the rod.
2. Check for overheating. Overheating is visible as a bluish bearing surface color caused by inadequate lubrication or excessive
RPM.
3. Check for rust. Rust formation on bearing surfaces causes uneven pitting of surfaces.
a - Pitting
a
8685
a
8686
a
8688