Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 141Get this manual
Cleaning and Inspection Cylinder Block and Crankcase Cover
IMPORTANT: Crankcase cover and cylinder block are matched, line-bored assembly and never should be mismatched by using different crankcase cover or
Special Service Information
Grooves In Cylinder Block Caused By Crankshaft Sealing Rings Grooves in cylinder block caused by crankshaft sealing rings are not problemexcept if installing new crankshaft and the new sealing rings on crankshaft do not line up with existing grooves in cylinder blockIf installing new crankshaft, refer to crankshaft installation, Powerhead Reassembly section to determine if powerhead can be used
cylinder block
Cylinder Bores