Mercury Mariner Outboard 225 3 Litre Service Manual 1994, Page 146Get this manual
7 Uneven WearUneven wear could be caused by bent connecting rod
IMPORTANT: Clean connecting rod just enough to clean up bearing surfacesDO NOT continue to clean after marks are removed from bearing surfaces
aUneven Wear Between Arrows
If necessary, clean connecting rod bearing surfaces, as follows: aBe sure that "etched" marks on connecting rod (crankshaft end) are perfectly aligned with "etched" marks on connecting rod capTighten connecting rod cap attaching bolts secu rely52323
Clean PISTON PIN END of connecting rodusing same method as in Step "b precedingbut using 320 grit carborundum cloth instead of crocus clothM ,