Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-42794--1, Page 355Get this manual
4Install cover (a) and fill strainer 3Remove tank receptacle nut (a) us ng 23mm wrench Hold receptacle inside tank using AutoBlend Service Tool Wrench (91-16748)
4Remove O-ring (a) from tank receptacle (b)
Internal Oil Filter Removal
1Remove main body assemblySee page 152Remove internal oil filter (a) by sliding the assembly down the oil pump inlet tube (b) Then remove spring (c)